Diaper structure with enhanced tactile softness attributes

ABSTRACT

A diaper structure with enhanced softness attributes is disclosed. The diaper structure may include an innermost layer formed of a first nonwoven web, and an outermost layer formed of a second nonwoven web. The first and second nonwoven webs may have a combined basis weight of at least about 30 gsm. The ratio of the first web basis weight to the second web basis weight may range from 30/70 to 70/30.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of, and claims priority under 35U.S.C. §120 to, U.S. patent application Ser. No. 13/953,772, filed onJul. 30, 2013, which claims the benefit, under 35 USC §119(e), of U.S.Provisional Patent Application Ser. No. 61/678,163, filed on Aug. 1,2012, the entire disclosures of which are fully incorporated byreference herein.

BACKGROUND OF THE INVENTION

The business of manufacturing and marketing disposable absorbentarticles for personal care or hygiene (such as disposable diapers,training pants, adult incontinence undergarments, feminine hygieneproducts, breast pads, care mats, bibs, wound dressing products, and thelike) is relatively capital intensive and highly competitive. Tomaintain or grow their market share and thereby maintain a successfulbusiness, manufacturers of such articles must continually strive toenhance their products in ways that serve to differentiate them fromthose of their competitors, while at the same time controlling costs soas to enable competitive pricing and the offering to the market of anattractive value-to-price proposition.

One way in which some manufacturers may seek to enhance such products isthrough enhancements to softness. Parents and caregivers naturally seekto provide as much comfort as they can for their babies, and utilizingproducts such as disposable diapers that they perceive as relativelysoft provides reassurance that they are doing what they can to providecomfort in that context. With respect to other types of disposableabsorbent articles that are designed to be applied and/or worn close tothe skin, perceptions of softness can reassure the wearer or caregiverthat the article will be comfortable. Thus, the manufacturer of sucharticles may devote efforts toward enhancing the softness attributes ofthe structure of an article and of the various materials used to makethe article, including the outermost materials of the article (e.g.materials that are visible and/or exposed to the wearer's skin ortouch).

It is believed that humans' perceptions of softness of an absorbentarticle can be affected by tactile signals, auditory signals and visualsignals.

Tactile softness signals may be affected by a variety of the articlecomponents' features and properties that have effect on its tactilefeel. For example, many absorbent articles have outermost layercomponents formed of nonwoven materials, and attributes of suchmaterials including but not limited to loft, fiber shape, thickness anddensity, basis weight, microscopic pliability and flexibility ofindividual fibers, macroscopic pliability and flexibility of thenonwoven web as formed by the fibers, surface friction characteristics,number of loose fibers or free fiber ends, and other features, mayimpact the tactile signals the article conveys.

Perceptions of softness also may be affected by auditory signals, e.g.,whether and to what extent the materials of the article make audiblerustling, crinkling or other noises when touched or manipulated.

It is believed that perceptions of softness of a material also may beaffected by visual signals, i.e., its visual appearance. It is believedthat, if materials forming an absorbent article look relatively soft toa person, it is much more likely that the person will perceive thearticle as having relative tactile softness as well. Visual impressionsof softness may be affected by a variety of features and properties,including but not limited to color, opacity, light reflectivity,refractivity or absorption, apparent thickness/caliper, fiber size anddensity, and macroscopic physical surface features.

As a result of the complexity of the mix of the above-describedcharacteristics and the subjective nature of individual perceptions, tothe extent softness is considered an attribute of an absorbent article,it may elude precise measurement or quantification. Although severalmethods for measuring and evaluating material features that are believedto affect softness signals have been developed, there are no standard,universally accepted units or methods of measurement for softness. It isa subjective, relative concept, difficult to characterize in anobjective way. Because softness is difficult to characterize, it canalso be difficult to affect in a predictable way, through changes oradjustments to specifications in materials or manufacturing processes.

Complicating efforts to define and enhance softness is the fact thatdiffering individuals will have differing individual physiological andexperiential frames of reference and perceptions concerning whatfeatures and properties will cause them to perceive softness to a lesseror greater extent.

Various efforts have been made to provide or alter features of nonwovenweb materials with the objective of enhancing loft and/or consumerperceptions of softness. These efforts have included selection and/ormanipulation of fiber chemistry, basis weight, loft, fiber density,configuration and size, tinting and/or opacifying, embossing or bondingin various patterns, etc. Various approaches are described in, forexample, co-pending U.S. application Ser. No. 13/428,404 by Xu et al.

Efforts at enhancing softness attributes and increasing perceptions ofsoftness to date have had varying degrees of success, but have left roomfor improvements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a disposable diaper shown laid outhorizontally in a relaxed condition, wearer-facing surfaces up;

FIG. 1B is a plan view of a disposable diaper shown laid outhorizontally in a stretched out, flattened state (stretched out againstelastic contraction induced by the presence of elastic members),wearer-facing surfaces facing the viewer;

FIG. 2A is a cross section of the diaper depicted in FIGS. 1A and 1B,taken through line 2-2 in those figures;

FIG. 2B is a schematic cross section of a portion of a laminate of apolymeric film and a nonwoven web, taken through a pattern of bondimpressions in the nonwoven web;

FIG. 3 is a simplified schematic view of a batt moving through the nipbetween calender rollers to form a calender-bonded nonwoven web;

FIG. 4A is a view of a pattern of bonding surface shapes of bondingprotrusions that may be imparted to the surface of a calender roller, tocreate a corresponding pattern of consolidating bond impressions havingbond shapes in a nonwoven web;

FIG. 4B is a view of another pattern of bonding surface shapes ofbonding protrusions that may be imparted to the surface of a calenderroller, to create another corresponding pattern of consolidating bondimpressions having bond shapes in a nonwoven web;

FIG. 4C is a magnified view of the pattern of bonding surface shapes ofbonding protrusions or consolidating bond impressions having bond shapesappearing in FIG. 4B;

FIG. 5A is a view of another pattern of bonding surface shapes ofbonding protrusions that may be imparted to the surface of a calenderroller, to create another corresponding pattern of consolidating bondimpressions having bond shapes in a nonwoven web;

FIG. 5B is a magnified view of the pattern of bonding surface shapes ofbonding protrusions or consolidating bond impressions having bond shapesappearing in FIG. 5A;

FIG. 5C is a magnified view of the pattern of bonding surface shapes ofbonding protrusions or consolidating bond impressions having bondingimpressions appearing in FIG. 5A;

FIG. 6A is a view of another pattern of bonding surface shapes ofbonding protrusions that may be imparted to the surface of a calenderroller, to create another corresponding pattern of consolidating bondimpressions having bond shapes in a nonwoven web;

FIG. 6B is a magnified view of the pattern of bonding surface shapes ofbonding protrusions or consolidating bond impressions having bond shapesappearing in FIG. 6A; and

FIG. 7 is a view of another pattern of bonding surface shapes of bondingprotrusions that may be imparted to the surface of a calender roller, tocreate another corresponding pattern of consolidating bond impressionshaving bond shapes in a nonwoven web.

DESCRIPTION OF EXAMPLES Definitions

“Absorbent article” refers to devices that absorb and contain bodyexudates, and, more specifically, refers to devices that are placedagainst or in proximity to the body of the wearer to absorb and containthe various exudates discharged from the body. Absorbent articles mayinclude diapers, training pants, adult incontinence undergarments andpads, feminine hygiene pads, breast pads, care mats, bibs, wounddressing products, and the like. As used herein, the term “exudates”includes, but is not limited to, urine, blood, vaginal discharges,breast milk, sweat and fecal matter.

“Absorbent core” means a structure typically disposed between a topsheetand backsheet of an absorbent article for absorbing and containingliquid received by the absorbent article. The absorbent core may alsoinclude a cover layer or envelope. The cover layer or envelope maycomprise a nonwoven. In some examples, the absorbent core may includeone or more substrates, an absorbent polymer material, and athermoplastic adhesive material/composition adhering and immobilizingthe absorbent polymer material to a substrate, and optionally a coverlayer or envelope.

“Absorbent polymer material,” “absorbent gelling material,” “AGM,”“superabsorbent,” and “superabsorbent material” are used hereininterchangeably and refer to cross linked polymeric materials that canabsorb at least 5 times their weight of an aqueous 0.9% saline solutionas measured using the Centrifuge Retention Capacity test (Edana441.2-01).

“Absorbent particulate polymer material” is used herein to refer to anabsorbent polymer material which is in particulate form so as to beflowable in the dry state.

“Absorbent particulate polymer material area” as used herein refers tothe area of the core wherein the first substrate and second substrateare separated by a multiplicity of superabsorbent particles. There maybe some extraneous superabsorbent particles outside of this area betweenthe first substrate 64 and second substrate.

“Airfelt” is used herein to refer to comminuted wood pulp, which is aform of cellulosic fiber.

A “batt” is used herein to refer to fiber materials prior to beingconsolidated in a final calendering process as described herein. A“batt” comprises individual fibers, which are usually unbonded to eachother, although a certain amount of pre-bonding between fibers may beperformed and is also included in the meaning, such as may occur duringor shortly after the lay-down of fibers in a spunlaying process, or asmay be achieved be a pre-calendering. This pre-bonding, however, stillpermits a substantial number of the fibers to be freely moveable suchthat they can be repositioned. A “batt” may comprise several strata,such as may result from depositing fibers from several beams in aspunlaying process.

“Bicomponent” refers to fiber having a cross-section comprising twodiscrete polymer components, two discrete blends of polymer components,or one discrete polymer component and one discrete blend of polymercomponents. “Bicomponent fiber” is encompassed within the term“multicomponent fiber.” A Bicomponent fiber may have an overall crosssection divided into two or more subsections of the differing componentsof any shape or arrangement, including, for example, coaxialsubsections, core-and-sheath subsections, side-by-side subsections,radial subsections, etc.

“Bond area percentage” on a nonwoven web is a ratio of area occupied bybond impressions, to the total surface area of the web, expressed as apercentage, and measured according to the Bond Area Percentage Methodset forth herein.

“Bonding roller,” “calender roller” and “roller” are usedinterchangeably.

A “bond impression” in a nonwoven web is the surface structure createdby the impression of a bonding protrusion on a calender roller into anonwoven web. A bond impression is a location of deformed, intermeshedor entangled, and melted or thermally fused, materials from fiberssuperimposed and compressed in a z-direction beneath the bondingprotrusion, which form a bond. The individual bonds may be connected inthe nonwoven structure by loose fibres between them. The shape and sizeof the bond impression approximately corresponds to the shape and sizeof the bonding surface of a bonding protrusion on the calender roller.

A “column” of bonds on a nonwoven web is a group of nearest neighboringbonds of like shape and rotational orientation that are arranged alongthe line that extends most predominately in the machine direction.

“Cross direction” (CD)—with respect to the making of a nonwoven webmaterial and the nonwoven web material, refers to the direction alongthe web material substantially perpendicular to the direction of forwardtravel of the web material through the manufacturing line in which theweb material is manufactured. With respect to a batt moving through thenip of a pair of calender rollers to form a bonded nonwoven web, thecross direction is perpendicular to the direction of movement throughthe nip, and parallel to the nip.

“Disposable” is used in its ordinary sense to mean an article that isdisposed or discarded after a limited number of usage events overvarying lengths of time, for example, less than about 20 events, lessthan about 10 events, less than about 5 events, or less than about 2events.

“Diaper” refers to an absorbent article generally worn by infants andincontinent persons about the lower torso so as to encircle the waistand legs of the wearer and that is specifically adapted to receive andcontain urinary and fecal waste. As used herein, term “diaper” alsoincludes “pant” which is defined below.

“Fiber” and “filament” are used interchangeably.

“Fiber diameter” is expressed in units of μm. The terms “grams of fiberper 9000 m” (denier or den) or “grams of fiber per 10000 m” (dTex) areused to describe the fineness or coarseness of fibers, which are linkedto the diameter (when assumed to be circular) by the density of theemployed material(s).

“Film”—means a skin-like or membrane-like layer of material formed ofone or more polymers, which does not have a form consistingpredominately of a web-like structure of consolidated polymer fibersand/or other fibers.

“Length” or a form thereof, with respect to a diaper or training pant,refers to a dimension measured along a direction perpendicular to thewaist edges and/or parallel to the longitudinal axis.

“Machine direction” (MD)—with respect to the making of a nonwoven webmaterial and the nonwoven web material, refers to the direction alongthe web material substantially parallel to the direction of forwardtravel of the web material through the manufacturing line in which theweb material is manufactured. With respect to a nonwoven batt movingthrough the nip of a pair of calender rollers to form a bonded nonwovenweb, the machine direction is parallel to the direction of movementthrough the nip, and perpendicular to the nip.

“Monocomponent” refers to fiber formed of a single polymer component orsingle blend of polymer components, as distinguished from bicomponent ormulticomponent fiber.

“Multicomponent” refers to fiber having a cross-section comprising morethan one discrete polymer component, more than one discrete blend ofpolymer components, or at least one discrete polymer component and atleast one discrete blend of polymer components. “Multicomponent fiber”includes, but is not limited to, “bicomponent fiber.” A multicomponentfiber may have an overall cross section divided into subsections of thediffering components of any shape or arrangement, including, forexample, coaxial subsections, core-and-sheath subsections, side-by-sidesubsections, radial subsections, islands-in-the-sea, etc.

A “nonwoven” is a manufactured sheet or web of directionally or randomlyoriented fibers which are first formed into a batt and then consolidatedand bonded together by friction, cohesion, adhesion or one or morepatterns of bonds and bond impressions created through localizedcompression and/or application of pressure, heat, ultrasonic or heatingenergy, or a combination thereof. The term does not include fabricswhich are woven, knitted, or stitch-bonded with yarns or filaments. Thefibers may be of natural or man-made origin and may be staple orcontinuous filaments or be formed in situ. Commercially available fibershave diameters ranging from less than about 0.001 mm to more than about0.2 mm and they come in several different forms: short fibers (known asstaple, or chopped), continuous single fibers (filaments ormonofilaments), untwisted bundles of continuous filaments (tow), andtwisted bundles of continuous filaments (yarn). Nonwoven fabrics can beformed by many processes including but not limited to meltblowing,spunbonding, spunmelting, solvent spinning, electrospinning, carding,film fibrillation, melt-film fibrillation, airlaying, dry-laying,wetlaying with staple fibers, and combinations of these processes asknown in the art. The basis weight of nonwoven fabrics is usuallyexpressed in grams per square meter (gsm).

“Opacity” is a numeric value relating to the ability of a web materialto transmit light therethrough, measured according the OpacityMeasurement Method set forth herein.

“Pant” or “training pant”, as used herein, refer to disposable garmentshaving a waist opening and leg openings designed for infant or adultwearers. A pant may be placed in position on the wearer by inserting thewearer's legs into the leg openings and sliding the pant into positionabout a wearer's lower torso. A pant may be preformed by any suitabletechnique including, but not limited to, joining together portions ofthe article using refastenable and/or non-refastenable bonds (e.g.,seam, weld, adhesive, cohesive bond, fastener, etc.). A pant may bepreformed anywhere along the circumference of the article (e.g., sidefastened, front waist fastened). While the terms “pant” or “pants” areused herein, pants are also commonly referred to as “closed diapers,”“prefastened diapers,” “pull-on diapers,” “training pants,” and“diaper-pants”. Suitable pants are disclosed in U.S. Pat. No. 5,246,433,issued to Hasse et al. on Sep. 21, 1993; U.S. Pat. No. 5,569,234, issuedto Buell et al. on Oct. 29, 1996; U.S. Pat. No. 6,120,487, issued toAshton on Sep. 19, 2000; U.S. Pat. No. 6,120,489, issued to Johnson etal. on Sep. 19, 2000; U.S. Pat. No. 4,940,464, issued to Van Gompel etal. on Jul. 10, 1990; U.S. Pat. No. 5,092,861, issued to Nomura et al.on Mar. 3, 1992; U.S. Patent Publication No. 2003/0233082 A1, entitled“Highly Flexible And Low Deformation Fastening Device”, filed on Jun.13, 2002; U.S. Pat. No. 5,897,545, issued to Kline et al. on Apr. 27,1999; U.S. Pat. No. 5,957,908, issued to Kline et al. on Sep. 28, 1999.

When used as an adjective in connection with a component of a material,the term “predominately” means that the component makes up greater than50% by weight of the material. When used as an adjective in connectionwith a directional orientation of a physical feature or geometricattribute thereof, “predominately” means the feature or attribute has aprojection onto a line extending along the direction indicated, greaterin length than the projection onto a line perpendicular thereto. Withinother contexts, the term “predominantly” refers to a condition whichimparts a substantial effect on a property or feature. Thus, when amaterial comprises “predominantly” a component said to impart aproperty, this component imparts a property that the material otherwisewould not exhibit. For example, if a material comprises “predominantly”heat-fusible fibers, the quantity and components of these fibers must besufficient to allow heat fusion of the fibers.

A “bonding protrusion” or “protrusion” is a feature of a bonding rollerat its radially outermost portion, surrounded by recessed areas.Relative the rotational axis of the bonding roller, a bonding protrusionhas a radially outermost bonding surface with a bonding surface shapeand a bonding surface shape area, which generally lies along an outercylindrical surface with a substantially constant radius from thebonding roller rotational axis; however, protrusions having bondingsurfaces of discrete and separate shapes are often small enough relativethe radius of the bonding roller that the bonding surface may appearflat/planar; and the bonding surface shape area is closely approximatedby a planar area of the same shape. A bonding protrusion may have sidesthat are perpendicular to the bonding surface, although usually thesides have an angled slope, such that the cross section of the base of abonding protrusion is larger than its bonding surface. A plurality ofbonding protrusions may be arranged on a calender roller in a pattern.The plurality of bonding protrusions has a bonding area per unit surfacearea of the outer cylindrical surface which can be expressed as apercentage, and is the ratio of the combined total of the bonding shapeareas of the protrusions within the unit, to the total surface area ofthe unit.

A “row” of bonds on a nonwoven web is a group of nearest neighboringbonds of like shape and rotational orientation that are arranged alongthe line that extends most predominately in the cross direction.

“Substantially cellulose free” is used herein to describe a portion ofan article, such as an absorbent core, that contains less than 10% byweight cellulosic fibers, less than 5% cellulosic fibers, less than 1%cellulosic fibers, no cellulosic fibers, or no more than an immaterialamount of cellulosic fibers. An immaterial amount of cellulosic materialwould not materially affect the thinness, flexibility, or absorbency ofan absorbent core.

“Substantially continuously distributed” as used herein indicates thatwithin the absorbent particulate polymer material area, the firstsubstrate 64 and second substrate 72 are separated by a multiplicity ofsuperabsorbent particles. It is recognized that there may be minorincidental contact areas between the first substrate 64 and secondsubstrate 72 within the absorbent particulate polymer material area.Incidental contact areas between the first substrate 64 and secondsubstrate 72 may be intentional or unintentional (e.g. manufacturingartifacts) but do not form geometries such as pillows, pockets, tubes,and the like.

“Tensile Strength” refers to the maximum tensile force (Peak Force) amaterial will sustain before tensile failure, as measured by the TensileStrength Measurement Method set forth herein.

“Thickness” and “caliper” are used herein interchangeably.

“Total Stiffness” refers to the measured and calculated value relatingto a material, according to the Stiffness measurement method set forthherein.

“Density” is the ratio of basis weight and thickness and indicates thebulkiness and fluffiness of the product, which are important propertiesof the nonwoven web according to the invention. The lower the value, thebulkier is the web.Density [kg/m³]=basis weight [g/m²]/thickness [mm].

“Width” or a form thereof, with respect to a diaper or training pant,refers to a dimension measured along a direction parallel to the waistedges and/or perpendicular to the longitudinal axis.

“Z-direction,” with respect to a web, means generally orthogonal orperpendicular to the plane approximated by the web along the machine andcross direction dimensions.

Description

Examples of the present invention include disposable absorbent articleshaving improved softness attributes.

FIG. 1A is a perspective view of a diaper 10 in a relaxed, laid-openposition as it might appear opened and lying on a horizontal surface.FIG. 1B is a plan view of a diaper 10 shown in a flat-out, uncontractedstate (i.e., without elastic induced contraction), shown with portionsof the diaper 10 cut away to show underlying structure. The diaper 10 isdepicted in FIG. 1B with its longitudinal axis 36 and its lateral axis38. Portions of the diaper 10 that contact a wearer are shown orientedupwards in FIG. 1A, and are shown facing the viewer in FIG. 1B. FIG. 2Ais a cross section of the diaper taken at line 2-2 in FIG. 1B.

The diaper 10 generally may comprise a chassis 12 and an absorbent core14 disposed in the chassis. The chassis 12 may comprise the main body ofthe diaper 10.

The chassis 12 may include a topsheet 18, which may be liquid pervious,and a backsheet 20, which may be liquid impervious. The absorbent core14 may be encased between the topsheet 18 and the backsheet 20. Thechassis 12 may also include side panels 22, elasticized leg cuffs 24,and an elastic waist feature 26. The chassis 12 may also comprise afastening system, which may include at least one fastening member 46 andat least one landing zone 48. One or more layers of the topsheet and/orbacksheet may be formed of a nonwoven web as described below.

The leg cuffs 24 and the elastic waist feature 26 may each typicallycomprise elastic members 28. One end portion of the diaper 10 may beconfigured as a first waist region 30 of the diaper 10. An opposite endportion of the diaper 10 may be configured as a second waist region 32of the diaper 10. An intermediate portion of the diaper 10 may beconfigured as a crotch region 34, which extends longitudinally betweenthe first and second waist regions 30 and 32. The crotch region 34 mayinclude from 33.3% to 50% of the overall length of the diaper 10, andeach of waist regions 30, 32 may correspondingly include from 25% to33.3% of the overall length of the diaper 10.

The waist regions 30 and 32 may include elastic elements such that theygather about the waist of the wearer to provide improved fit andcontainment (elastic waist feature 26). The crotch region 34 is thatportion of the diaper 10 which, when the diaper 10 is worn, is generallypositioned between the wearer's legs.

The diaper 10 may also include such other features including front andrear ear panels, waist cap features, elastics and the like to providebetter fit, containment and aesthetic characteristics. Such additionalfeatures are described in, e.g., U.S. Pat. Nos. 3,860,003 and 5,151,092.

In order to apply and keep diaper 10 in place about a wearer, the secondwaist region 32 may be attached by the fastening member 46 to the firstwaist region 30 to form leg opening(s) and an article waist. Whenfastened, the fastening system carries a tensile load around the articlewaist.

According to some examples, the diaper 10 may be provided with are-closable fastening system or may alternatively be provided in theform of a pant-type diaper. When the absorbent article is a diaper, itmay comprise a re-closable fastening system joined to the chassis forsecuring the diaper to a wearer. When the absorbent article is apant-type diaper, the article may comprise at least two side panelsjoined to the chassis and to each other to form a pant. The fasteningsystem and any component thereof may include any material suitable forsuch a use, including but not limited to plastics, films, foams,nonwoven, woven, paper, laminates, stretch laminates, activated stretchlaminates, fiber reinforced plastics and the like, or combinationsthereof. In some examples, the materials making up the fastening devicemay be flexible. In some examples, the fastening device may comprisecotton or cotton-like materials for additional softness or consumerperception of softness. The flexibility may allow the fastening systemto conform to the shape of the body and thus, reduce the likelihood thatthe fastening system will irritate or injure the wearer's skin.

For unitary absorbent articles, the chassis 12 and absorbent core 14 mayform the main structure of the diaper 10 with other features added toform the composite diaper structure. While the topsheet 18, thebacksheet 20, and the absorbent core 14 may be assembled in a variety ofwell-known configurations, preferred diaper configurations are describedgenerally in U.S. Pat. No. 5,554,145 entitled “Absorbent Article WithMultiple Zone Structural Elastic-Like Film Web Extensible Waist Feature”issued to Roe et al. on Sep. 10, 1996; U.S. Pat. No. 5,569,234 entitled“Disposable Pull-On Pant” issued to Buell et al. on Oct. 29, 1996; andU.S. Pat. No. 6,004,306 entitled “Absorbent Article WithMulti-Directional Extensible Side Panels” issued to Robles et al. onDec. 21, 1999.

The topsheet 18 may be fully or partially elasticized and/or may beforeshortened to create a void space between the topsheet 18 and theabsorbent core 14. Exemplary structures including elasticized orforeshortened topsheets are described in more detail in U.S. Pat. No.5,037,416 entitled “Disposable Absorbent Article Having ElasticallyExtensible Topsheet” issued to Allen et al. on Aug. 6, 1991; and U.S.Pat. No. 5,269,775 entitled “Trisection Topsheets for DisposableAbsorbent Articles and Disposable Absorbent Articles Having SuchTrisection Topsheets” issued to Freeland et al. on Dec. 14, 1993.

The backsheet 20 may be joined with the topsheet 18. The backsheet 20may serve to prevent the exudates absorbed by the absorbent core 14 andcontained within the diaper 10 from soiling other external articles thatmay contact the diaper 10, such as bed sheets and clothing. Referring toFIG. 2B, the backsheet 20 may be substantially impervious to liquids(e.g., urine) and may be formed of a laminate of a nonwoven 21 and athin polymeric film 23 such as a thermoplastic film having a thicknessof about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Nonwoven 21may be a nonwoven web as described herein. Suitable backsheet filmsinclude those manufactured by Tredegar Industries Inc. of Terre Haute,Ind. and sold under the trade names X15306, X10962, and X10964. Othersuitable backsheet materials may include breathable materials thatpermit vapors to escape from the diaper 10 while still preventing liquidexudates from passing through the backsheet 20. Exemplary breathablematerials may include materials such as woven webs, nonwoven webs,composite materials such as film-coated nonwoven webs, and microporousfilms such as manufactured by Mitsui Toatsu Co., of Japan under thedesignation ESPOIR and by EXXON Chemical Co., of Bay City, Tex., underthe designation EXXAIRE. Suitable breathable composite materialscomprising polymer blends are available from Clopay Corporation,Cincinnati, Ohio under the name HYTREL blend P1 8-3097. Other examplesof such breathable composite materials are described in greater detailin PCT Application No. WO 95/16746, published on Jun. 22, 1995 in thename of E. I. DuPont. Other breathable backsheets including nonwovenwebs and apertured formed films are described in U.S. Pat. No. 5,571,096issued to Dobrin et al. on Nov. 5, 1996.

In some examples, the backsheet of the present invention may have awater vapor transmission rate (WVTR) of greater than about 2,000 g/24h/m2, greater than about 3,000 g/24 h/m2, greater than about 5,000 g/24h/m2, greater than about 6,000 g/24 h/m2, greater than about 7,000 g/24h/m2, greater than about 8,000 g/24 h/m2, greater than about 9,000 g/24h/m2, greater than about 10,000 g/24 h/m2, greater than about 11,000g/24 h/m2, greater than about 12,000 g/24 h/m2, greater than about15,000 g/24 h/m2, measured according to WSP 70.5 (08) at 37.8 0 C and60% Relative Humidity.

Suitable nonwoven web materials useful in the present invention include,but are not limited to spunbond, meltblown, spunmelt, solvent-spun,electrospun, carded, film fibrillated, melt-film fibrillated, air-laid,dry-laid, wet-laid staple fibers, and other and other nonwoven webmaterials formed in part or in whole of polymer fibers, as known in theart. A suitable nonwoven web material may also be an SMS material,comprising a spunbonded, a melt-blown and a further spunbonded stratumor layer or any other combination of spunbonded and melt-blown layers,such as a SMMS or SSMMS etc. Examples include one or more layers offibers with diameters below 1 micron (nanofibers and nanofiber layers);examples of these rise in combinations of SMS, SMNS, SSMNS or SMNMSnonwoven webs (where “N” designates a nanofiber layer). In someexamples, permanently hydrophilic non-wovens, and in particular,nonwovens with durably hydrophilic coatings may be desirable. Typically,the suitable non-woven is air permeable. Typically the suitable nonwovenis water or liquid permeable, but may also be water impermeable byreason of fiber size and density, and hydrophobicity of the fibers.Water or liquid permeability may be enhanced by treatments to render thefibers hydrophilic, as discussed below.

The nonwoven web may be formed predominately of polymeric fibers. Insome examples, suitable non-woven fiber materials may include, but arenot limited to polymeric materials such as polyolefins, polyesters,polyamide, or specifically polypropylene (PP), polyethylene (PE),poly-lactic acid (PLA), polyethylene terephthalate (PET) and/or blendsthereof. Nonwoven fibers may be formed of, or may include as additivesor modifiers, components such as aliphatic polyesters, thermoplasticpolysaccharides, or other biopolymers (bio-based or renewable polymers).

The individual fibers may be monocomponent or multicomponent. Themulticomponent fibers may be bicomponent, such as in a core-and-sheathor side-by-side arrangement. Often, the individual components comprisealiphatic polyolefins such as polypropylene or polyethylene, or theircopolymers, aliphatic polyesters, thermoplastic polysaccharides or otherbiopolymers.

Further useful nonwovens, fiber compositions, formations of fibers andnonwovens and related methods are described in U.S. Pat. No. 6,645,569to Cramer et al., U.S. Pat. No. 6,863,933 to Cramer et al., U.S. Pat.No. 7,112,621 to Rohrbaugh et al.; co-pending U.S. patent applicationSer. Nos. 10/338,603 and 10/338,610 by Cramer et al., and Ser. No.13/005,237 by Lu et al., the disclosures of which are incorporated byreference herein.

Some polymers used for nonwoven fiber production may be inherentlyhydrophobic, and for certain applications they may be surface treated orcoated with various agents to render them hydrophilic. A surface coatingmay include a surfactant coating. One such surfactant coating isavailable from Schill & Silacher GmbH, Böblingen, Germany, under theTradename Silastol PHP 90.

Another way to produce nonwovens with durably hydrophilic coatings, isvia applying a hydrophilic monomer and a radical polymerizationinitiator onto the nonwoven, and conducting a polymerization activatedvia UV light resulting in monomer chemically bound to the surface of thenonwoven as described in co-pending U.S. Patent Publication No.2005/0159720.

Another way to produce hydrophilic nonwovens made predominantly fromhydrophobic polymers such as polyolefins is to add hydrophilic additivesinto the melt prior to extrusion.

Another way to produce nonwovens with durably hydrophilic coatings is tocoat the nonwoven with hydrophilic nanoparticles as described inco-pending applications U.S. Pat. No. 7,112,621 to Rohrbaugh et al. andin PCT Application Publication WO 02/064877.

Typically, nanoparticles have a largest dimension of below 750 nm.Nanoparticles with sizes ranging from 2 to 750 nm may be economicallyproduced. An advantage of nanoparticles is that many of them can beeasily dispersed in water solution to enable coating application ontothe nonwoven, they typically form transparent coatings, and the coatingsapplied from water solutions are typically sufficiently durable toexposure to water. Nanoparticles can be organic or inorganic, syntheticor natural. Inorganic nanoparticles generally exist as oxides,silicates, and/or carbonates. Typical examples of suitable nanoparticlesare layered clay minerals (e.g., LAPONITE™ from Southern Clay Products,Inc. (USA), and Boehmite alumina (e.g., Disperal P2™ from North AmericanSasol. Inc.). According to one example, a suitable nanoparticle coatednon-woven is that disclosed in the co-pending patent application Ser.No. 10/758,066 entitled “Disposable absorbent article comprising adurable hydrophilic core wrap” by Ponomarenko and Schmidt.

In some cases, the nonwoven web surface can be pre-treated with highenergy treatment (corona, plasma) prior to application of nanoparticlecoatings. High energy pre-treatment typically temporarily increases thesurface energy of a low surface energy surface (such as PP) and thusenables better wetting of a nonwoven by the nanoparticle dispersion inwater.

Notably, hydrophilic non-wovens are also useful in other parts of anabsorbent article. For example, topsheets and absorbent core layerscomprising permanently hydrophilic non-wovens as described above havebeen found to work well.

A nonwoven also may include other types of surface coating. In oneexample, the surface coating may include a fiber surface modifying agentthat reduces surface friction and enhances tactile lubricity. Preferredfiber surface modifying agents are described in U.S. Pat. Nos. 6,632,385and 6,803,103; and U.S. Pat. App. Pub. No. 2006/0057921.

According to one example, the nonwoven may comprise a material thatprovides good recovery when external pressure is applied and removed.Further, according to one example, the nonwoven may comprise a blend ofdifferent fibers selected, for example from the types of polymericfibers described above. In some embodiments, at least a portion of thefibers may exhibit a spiral curl which has a helical shape. According toone example, the fibers may include bicomponent fibers, which areindividual fibers each comprising different materials, usually a firstand a second polymeric material. It is believed that the use ofside-by-side bi-component fibers is beneficial for imparting a spiralcurl to the fibers.

In order to enhance softness perceptions of the absorbent article,nonwovens forming the backsheet may be hydroenhanced or hydroengorged.Hydroenhanced/hydroengorged nonwovens are described in U.S. Pat. Nos.6,632,385 and 6,803,103, and U.S. Pat. App. Pub. No. 2006/0057921, thedisclosures of which are incorporated herein by reference.

A nonwoven may also be treated by a “selfing” mechanism. By “selfing”nonwovens, high densities of loops (>150 in 2) may be formed whichprotrude from the surface of the nonwoven substrate. Since these loopsact as small flexible brushes, they create an additional layer ofspringy loft, which may enhance softness. Nonwovens treated by a selfingmechanism are described in U.S. Pat. App. Pub. No. US 2004/0131820.

Any of the nonwoven types described herein may be used for the topsheet,backsheet outer layer, loops component in a hook-and-loop fasteningsystem of an absorbent article, or any other portion of a manufacturedarticle such as cleansing wipes and other personal hygiene products,dusters and dusting cloths, household cleaning cloths and wipes, laundrybags, dryer bags and sheets comprising a layer formed of nonwoven web.

The absorbent core generally may be disposed between the topsheet 18 andthe backsheet 20. It may include one or more layers, such as a firstabsorbent layer 60 and a second absorbent layer 62.

The absorbent layers 60, 62 may include respective substrates 64, 72, anabsorbent particulate polymer material 66, 74 disposed on substrates 64,72, and a thermoplastic adhesive material 68, 76 disposed on and/orwithin the absorbent particulate polymer material 66, 74 and at leastportions of the substrates 64, 72 as an adhesive for immobilizing theabsorbent particulate polymer material 66, 74 on the substrates 64, 65.

The substrate 64 of the first absorbent layer 60 may be referred to as adusting layer and has a first surface which faces the backsheet 20 and asecond surface which faces the absorbent particulate polymer material66. Likewise, the substrate 72 of the second absorbent layer 62 may bereferred to as a core cover and has a first surface facing the topsheet18 and a second surface facing the absorbent particulate polymermaterial 74.

The first and second substrates 64 and 72 may be adhered to one anotherwith adhesive about the periphery to form an envelope about theabsorbent particulate polymer materials 66 and 74 to hold the absorbentparticulate polymer material 66 and 74 within the absorbent core 14.

The substrates 64, 72 may be of one or more nonwoven materials, and maybe liquid permeable.

As illustrated in FIG. 2A, the absorbent particulate polymer material66, 74 may be deposited on the respective substrates 64, 72 in clusters90 of particles to form a grid pattern comprising land areas 94 andjunction areas 96 between the land areas 94. Land areas 94 are areaswhere the thermoplastic adhesive material does not contact the nonwovensubstrate or the auxiliary adhesive directly; junction areas 96 areareas where the thermoplastic adhesive material does contact thenonwoven substrate or the auxiliary adhesive directly. The junctionareas 96 in the grid pattern contain little or no absorbent particulatepolymer material 66 and 74. The land areas 94 and junction areas 96 canhave a variety of shapes including, but not limited to, circular, oval,square, rectangular, triangular, and the like. First and second layers60, 62 may be combined to form the absorbent core 14. Examples ofsuitable absorbent articles and cores are described in U.S. applicationSer. No. 12/141,122; U.S. Pat. Nos. 7,744,576 and 7,750,203; and PCTPub. No. WO 2009/060384, which describe core structures having arelatively low quantity of cellulosic fibers (e.g. less than 40% of thecombined weight of cellulose fibers and absorbent polymer material), orare even substantially cellulose-free.

Signal ingredients may be incorporated into one or more components ofthe absorbent article. Signal ingredients may include, but are notlimited to, vitamins A, E, D, and C, panthenol, niacin, omega 3 oils,cocoa butter, beeswax, cashmere, sweet almond oil, jojoba, oatmeal,aloe, cotton, honey, and silk. These signal ingredients may be added toan absorbent article for the purpose of signaling a benefit to theconsumer. As an example, one or more of these signal ingredients may beadded to a lotion that may be applied to an absorbent article component.The signal ingredient alone, or in a lotion, may be applied to thetopsheet, backsheet, or any other component of the absorbent article.The lotion may comprise less than about 0.1% by weight, less than about0.01% by weight, less than about 0.006% by weight, less than about0.005% by weight, less than about 0.004% by weight, less than about0.003% by weight, less than about 0.002% by weight, and less than about0.001% by weight of the signal ingredient.

Additionally, a signal ingredient may, in combination with otherabsorbent article features, result in an unexpected synergy forcommunicating a benefit to the consumer. As an example, consumers mayrespond unexpectedly more favorably to an absorbent article that is thinand perceptibly soft in combination with a communication that lotion inthe diaper comprises vitamin E than they would respond to eithercommunication on its own.

An example of a diaper lotion comprising vitamin E as a signalingredient may include the following formula: PET/StOH Mix (ratio=1.41)94.0% to 99.8% (by weight) Aloe Extract 0.1% to 3.0% (by weight) VitaminE 0.001% to 0.1% (by weight). Further, vitamin E may be used in itsnatural form or esters of natural vitamin E may be used (e.g., vitamin Eacetate). U.S. App. Pub. Nos. 2002/0143304; 2004/0175343; 2003/0077307;U.S. Pat. Nos. 5,643,588; 5,635,191; 5,607,760; 6,861,571; and PCTApplication Nos. WO 00/69481; and WO 98/24391 disclose various absorbentarticle lotions that signal ingredients may be added to.

The foregoing description describes features of an absorbent article,any combination of which can be employed to enhance consumer perceptionsof softness of the article. In addition, however, it is believed thatmanufacturing a nonwoven web, and using it as a component of anabsorbent article including, e.g., a topsheet 18 and/or backsheet 20(see FIGS. 2A, 2B), according to the following description, provides forenhancement of loft of the component, and has synergistic effects withrespect to enhancing perceptions of softness of the article as a whole.At the same time, counterintuitively, features described below mayenhance tensile strength of the nonwoven web, and consequently, of thetopsheet, backsheet or other component formed of it. When attempting toimprove softness signals, preserving or enhancing tensile strength of anonwoven may be of particular interest in absorbent articles for atleast two reasons. First, the nonwoven web may typically be required tosustain certain minimum tensile forces and undergo sufficiently lowchanges in dimension so as to be effectively processable in downstreammanufacturing operations. Second, the nonwoven web typically may be asubstantial contributor to structural integrity of a the manufacturedproduct, such as a disposable diaper, in which the backsheet may berequired to sustain forces resulting from application/donning on awearer (e.g., when a caregiver tugs on fastening members to apply adiaper), wearer movements, and weight and bulk contained and sustainedby the backsheet when the diaper is loaded with the wearer's exudates.

As previously noted, referring to FIG. 2B, a backsheet 20 may be formedof a laminate of a nonwoven 21 and a thin polymeric film 23. Thenonwoven and film may be bonded in the laminating process by adhesive orany other suitable means. In some examples, the polymeric film may havea thickness of about 0.012 mm (0.5 mil) to about 0.051 mm (2.0 mils). Inorder to achieve the desired overall visual appearance, the opacity andwhiteness of the backsheet laminate may be enhanced by addition of, forexample, calcium carbonate (CaCO₃) to the film during its formation.Inclusion of fine particles of CaCO₃ cause the formation of microporesabout the particles upon stretching, or biaxial stretching in processingof the film, which serve to make the resulting film air- andvapor-permeable (thus, “breathable”, reducing the likelihood of skinoverhydration and thereby reducing the likelihood of conditions such asdiaper rash). The CaCO₃ particles and the resulting micropores in thefilm also serve to enhance its opacity. Examples of suitable filmsinclude MICROPRO microporous films, and films designated BR137P andBR137U, available from Clopay Corporation, Mason, Ohio. In someexamples, the polymeric film may be formed of components, and asdescribed, in U.S. application Pub. No. 2008/0306463, and may includesome or all of the features and/or components described therein, thatreduce the film's vulnerability to glue “burn-through.”

The nonwoven 21 may be formed from one or more resins of polyolefins,polyesters, polyamide including but not limited to polypropylene (PP),polyethylene (PE), and polyethylene terephthalate (PET), poly-lacticacid (PLA), and blends thereof. Resins including polypropylene may beparticularly useful because of polypropylene's relatively low cost andsurface friction properties of fibers formed from it (i.e., they have arelatively smooth, slippery tactile feel). Resins including polyethylenemay also be desirable because of polyethylene's relativesoftness/pliability and even more smooth/slippery surface frictionproperties. Relative each other, PP currently has a lower cost andfibers formed from it have a greater tensile strength, while PEcurrently has a greater cost and fibers formed from it have a lowertensile strength but greater pliability and a more smooth/slippery feel.Accordingly, it may be desirable to form nonwoven web fibers from ablend of PP and PE resins, finding a balance of the best proportions ofthe polymers to balance their advantages and disadvantages. In someexamples, the fibers may be formed of PP/PE blends such as described inU.S. Pat. No. 5,266,392. Nonwoven fibers may be formed of, or mayinclude as additives or modifiers, components such as aliphaticpolyesters, thermoplastic polysaccharides, or other biopolymers.

The individual fibers may be monocomponent or multicomponent. Themulticomponent fibers may be bicomponent, such as in a core-and-sheathor side-by-side arrangement. Often, the individual components comprisealiphatic polyolefins such as polypropylene or polyethylene, or theircopolymers, aliphatic polyesters, thermoplastic polysaccharides or otherbiopolymers.

A batt may be formed from any of these resins by conventional methods,such as carding, meltblowing, spunlaying, airlaying, wet-laying etc. Apreferred execution relates to spunbonding processes, in which theresin(s) are heated and forced under pressure through spinnerets. Thespinnerets eject fibers of the polymer(s), which are then directed ontoa moving belt; as they strike the moving belt they may be laid down insomewhat random orientations, but often with a machine-directionorientation or bias, to form a spunlaid batt. The batt then may becalender-bonded to form the nonwoven web.

Nonwovens formed of any basis weight may be used. However, as noted inthe background, relatively higher basis weight, while having relativelygreater apparent caliper and loft, also has relatively greater cost. Onthe other hand, relatively lower basis weight, while having relativelylower cost, adds to the difficulty of providing a nonwoven that providessuperior tactile experience, and has suitable mechanical properties. Itis believed that the combination of features described herein strikes agood balance between controlling material costs while providing asuperior tactile experience and suitable mechanical properties. It isbelieved that the features of consolidating bond shapes and patternsdescribed herein may be particularly useful in applications of nonwovensof relatively low basis weights in some applications, in that it isbelieved that such features provide a way to enhance loft whilereducing, or at least without adding, basis weight. Accordingly, forsuch applications, a nonwoven having a basis weight from 6.0 to 50 gsm,more preferably from 8.0 to 35 gsm, even more preferably from 9.0 to 25gsm, and still more preferably from 10 to 20 gsm may be used. When usedas a component of an absorbent article such as a topsheet, a lower basisweight nonwoven may provide strikethrough superior to that of a higherbasis weight nonwoven. A lower basis weight nonwoven may be preferableto a higher basis weight one when used, for example, as a component of azero-strain stretch laminate, because it will be more accommodating ofan activation/incremental stretching process. In other applications,such as, for example, use of nonwovens to form products such asdisposable clothing articles, wipes or dusters, higher basis weights upto 100 gsm, or even 150 gsm, may be desired. It is believed that thefeatures of bonding protrusions, bonding shapes and bonding patternsdescribed herein may have beneficial effects on loft and/or softnessperception, even with nonwovens of such higher basis weights. Optimalbasis weight is dictated by the differing needs in each application, andcost concerns.

It is believed that the desired overall visual softness signals of abacksheet laminate may be better achieved when the backsheet laminate issubstantially white in color, and has an Opacity of at least 45%, morepreferably at least 70%, even more preferably at least 73%, and stillmore preferably at least 75%, as measured by the Opacity MeasurementMethod set forth below. Accordingly, it may be desirable to add awhite-tinting/opacifying agent also to the polymer(s) forming thepolymeric film, and to the polymer(s) supplying the spinnerets used toform the fibers of the nonwoven web.

It may be desirable that a white-tinting/opacifying agent be added tothe polymer resin that is spun to make the nonwoven. Adjusting theopacity of the nonwoven web, through addition of an opacifying agent,may be desirable, such that the nonwoven web has an Opacity of at least10%, more preferably at least 18%, and still more preferably at least40%.

While a variety of whitening/opacifying agents may suffice, it isbelieved that titanium dioxide (TiO₂) may be particularly effectivebecause of its brightness and relatively high refractive index. It isbelieved that addition of TiO₂ to the polymer(s) from which the fibersare to be formed, in an amount up to 5.0% by weight of the nonwoven, maybe effective to achieve the desired results. However, because TiO₂ is arelatively hard, abrasive material, inclusion of TiO₂ in amounts greaterthan 5.0% by weight may have deleterious effects, including wear and/orclogging of spinnerets; interruption and weakening of the structure ofthe fibers and/or calender bonds therebetween; undesirably increasingthe surface friction properties of the fibers (resulting in a lesssmooth tactile feel); and unacceptably rapid wear of downstreamprocessing equipment components. It is believed that the increasedopacity provided by whitener helps to produce a visually distinctive,soft appearance of the nonwoven. It also may be desired in someapplications that a coloring or tinting agent be added to one or morethe polymer resin(s) from which the nonwoven fibers will be spun.

Opacity can also be enhanced by using fiber having cross-sectionalshapes other than round and solid (non-hollow) geometries, namelytrilobal or multilobal cross-sections, or hollow configurations orcombinations thereof. Those non-circular cross-sectional shapes can alsoprovide advantages in terms of loft and compression resilience.

Spunbonding includes the step of calender-bonding the batt of spunlaidfibers, to consolidate them and bond them together to some extent tocreate the web as a fabric-like structure and enhance mechanicalproperties e.g., tensile strength, which may be desirable so thematerial can sufficiently maintain structural integrity and dimensionalstability in subsequent manufacturing processes, and in the finalproduct in use. Referring to FIG. 3, calender-bonding may beaccomplished by passing the batt 21 a through the nip between a pair ofrotating calender rollers 50, 51, thereby compressing and consolidatingthe fibers to form a nonwoven web 21. One or both of the rollers may beheated, so as to promote heating, plastic deformation, intermeshingand/or thermal bonding/fusion between superimposed fibers compressed atthe nip. The rollers may form operable components of a bonding mechanismin which they are urged together by a controllable amount of force, soas to exert the desired compressing force/pressure at the nip. In someprocesses an ultrasonic energy source may be included in the bondingmechanism so as to transmit ultrasonic vibration to the fibers, again,to generate heat energy within them and enhance bonding.

One or both of the rollers may have their circumferential surfacesmachined, etched, engraved or otherwise formed to have thereon a bondingpattern of bonding protrusions and recessed areas, so that bondingpressure exerted on the batt at the nip is concentrated at the bondingsurfaces of the bonding protrusions, and is reduced or substantiallyeliminated at the recessed areas. The bonding surfaces have bondingsurface shapes. As a result, an impressed pattern of bonds betweenfibers forming the web, having bond impressions and bond shapescorresponding to the pattern and bonding surface shapes of the bondingprotrusions on the roller, is formed on the nonwoven web. One rollersuch as roller 51 may have a smooth, unpatterned cylindrical surface soas to constitute an anvil roller, and the other roller 50 may be formedwith a pattern as described, to constitute a bonding pattern roller;this combination of rollers will impart a pattern on the web reflectingthe pattern on the bonding pattern roller. In some examples both rollersmay be formed with patterns, and in particular examples, differingpatterns that work in combination to impress a combination pattern onthe web such as described in, for example, U.S. Pat. No. 5,370,764.

A repeating pattern of bonding protrusions and recessed areas such as,for example, depicted in FIG. 4A, may be formed onto a bonding roller 50(FIG. 3). The rod-shaped bonding shapes 100 depicted in FIG. 4A depictraised surfaces of bonding protrusions on a roller, while the areasbetween them represent recessed areas 101. The bonding shapes 100 of thebonding protrusions impress like-shaped bond impressions on the web inthe calendering process.

The bonding protrusions on a roller will have a height, which may beexpressed as a difference between the radius of the roller at theoutermost (bonding) surfaces of the bonding protrusions, and the radiusof the roller at the recessed areas 101. The height may be adjusted withthe objective of minimizing the amount of material that must be removedfrom the roller surface by machining or etching to create the desiredshapes and pattern, while still providing for sufficient clearancebetween the roller bearing the bonding protrusions and the opposingroller, at the recessed areas 101, to accommodate passage of the battthrough the nip in areas of the batt not to be bonded (i.e., at therecessed areas), without substantially compressing it—because maximumloft/caliper is the objective. For webs of the type and basis weightcontemplated herein, a bonding protrusion height between 0.3 mm and 1.0mm may be desired, or more preferably, a bonding protrusion heightbetween 0.5 mm and 0.8 mm, or even a bonding protrusion height between0.6 mm and 0.7 mm. The bonding surfaces of the bonding protrusions mayhave an average area between 0.3 mm² and 10 mm². The bonding protrusionstypically have sides with an angled slope when viewed in cross sectionthrough the height thereof.

Nonwoven webs of the type contemplated herein may be calender-bonded atline speed greater than 300 m/min., or 600 m/min., or even 800 m/min.,or more, depending upon nonwoven web composition, basis weight, bondingpattern, and equipment and process variables selected. Referring againto FIG. 3, it will be appreciated that at such speeds, the batt 21 a andthe surfaces of rollers 50, 51 will entrain surrounding air and move ittoward the nip 52, as suggested by the arrows. Surface features of abonding roller 50, as described above, will enhance this effect. It isbelieved that, as entrained air is carried toward the nip, thedecreasing space between the rollers as the nip is approached creates azone of relatively higher, and increasing, air pressure in front of thenip 52. A portion of the entrained air under such higher pressure willbe urged into and further compressed in the nip 52, within the recessedareas of the bonding pattern on the roller, and within the intersticesof the fibers passing through the nip. It is believed that, as nonwovenweb 21 exits the nip 52, compressed air entrained within the fibers andpassing through the nip therewith encounters a zone of relatively lowerpressure on the exit side, and accelerates away from the nip in allunobstructed directions as a result. Thus, it is believed thatsubstantial air entrainment, air compression and complex air flows ofrelatively high velocity occur within and about the batt 21 a and web 21as a result of movement of the batt and rotation of the calender rollersin the calender-bonding process.

It is believed that surface features of a bonding roller including thebonding protrusions affect these air flows. Particularly at the nip, theprofiles of bonding protrusions present obstructions to airflow, whilethe recessed areas between the bonding protrusions present passageways.Thus, it is believed that for certain configurations, shapes, andpositions of bonding protrusions, as will be reflected in the bondimpressions created in the web, rotational orientation(s) and repeatingpatterns of the bonding shapes can be selected and formed to have abeneficial effect on these air flows. It is believed, further, thatpatterns of bonding protrusions having bonding surface shapes withcertain features, reflected in the bonding surfaces and the crosssections of the protrusions along planes substantially parallel with thebonding surfaces, rotational orientations relative the planeapproximated by the web surface, and spacing, may be employed to channelthese air flows in a way that causes them to reposition the fibersduring the calender bonding process, such as by teasing or fluffing thefibers, thus providing an enhanced calender-bonded nonwoven web havinggreater loft/caliper than a similar nonwoven web having otherconsolidated bond shapes and patterns, all other variables being thesame.

FIGS. 5A, 5B and 5C depict one example of a bonding pattern and bondingshapes that will be reflected in bond shapes of bond impressions in anonwoven web. Bonding shapes 100 represent the shapes of bondingsurfaces of bonding protrusions that may be imparted to a bonding rollerby etching, machining or other methods. Such bonding protrusions on abonding roller will impress bond impressions into a web, of like bondshapes, arranged in a like bonding pattern. Without intending to bebound by theory, it is believed that certain aspects and features of thedepicted shapes and pattern may have the beneficial effect describedabove.

Referring to FIG. 5B, the bonding shape 100 has a greatest measurablelength L, which is measured by identifying a shape length line 104intersecting the perimeter of the shape at points of intersection thatare the greatest distance apart that may be identified on the perimeter,i.e., the distance between the two farthest-most points on theperimeter. The bonding shape 100 has a greatest measurable width W whichis measured by identifying respective shape width lines 105 a, 105 bwhich are parallel to shape length line 104 and tangent to the shapeperimeter at one or more outermost points that are most distant fromshape length line 104 on either side of it, as reflected in FIG. 5b . Itwill be appreciated that, for some shapes (e.g., a semicircle), one ofshape width lines 105 a, 105 b may be coincident/colinear with shapelength line 104. Greatest measurable width W is the distance betweenshape width lines 105 a, 105 b. Shapes within the scope of the presentinvention have an aspect ratio of greatest measurable length L togreatest measurable width W of at least 2.5, more preferably at least2.7, and even more preferably at least 2.8. The bond shapes and sizesimpressed on the nonwoven web will reflect and correspond with thebonding shapes 100 and sizes thereof on the roller.

Still referring to FIG. 5B, a bonding shape 100 may have a shapeperimeter with a convex portion 102, lying on one side of the shapelength line 104. FIG. 5B shows also that the convex portion may have avarying radius or radii. The varying radius/radii of the convex portion102 may render the shape perimeter similar to the profile of the camberof an airfoil in cross section. Viewed another way, the cross-sectionalprofile of an airfoil has a convex portion and is asymmetric about anyline or axis that traverses the profile, which can be identified. Theconvex portion 102 may have a camber height CH measured as the distancebetween shape length line 104 and the shape width line 105 b that istangent to the convex portion 102. It is believed that, for maximumbeneficial impact on airflow, it may be desirable that the ratio betweencamber height CH and greatest measurable length L be 0.30 or less, morepreferably 0.25 or less, but greater than zero. It is believed that abonding protrusion having a cross section along a plane parallel thebonding surface, fitting this description, repeated and arranged in apattern, has beneficial effects on acceleration and deceleration of airthrough nonwoven fibers at and about the nip. Again, the bond shapes andsizes impressed on the nonwoven web will reflect and correspond with thebonding shapes and sizes on the roller.

The shape perimeter may have a convex portion with or without a varyingradius on both sides of shape length line 104, such that it has theoverall contour of an airfoil with symmetrical camber, in cross section.In another alternative, the shape perimeter may have a convex portion onone side of shape length line 104 and a straight portion on or on theother side of shape length line 104, such that it has the overallcontour of an airfoil/aircraft wing with asymmetrical camber, in crosssection. In another alternative, the shape perimeter may have a convexportion on one side of shape length line 104 and a concave portion 103disposed substantially opposite the concave portion, as reflected inFIG. 5B, such that it has the overall contour of an airfoil/aircraftwing with asymmetrical camber and relatively high-loft, low-speedfeatures, in cross section.

The extent of the concavity of concave portion 103 may be quantified bymeasuring the depth thereof, relative the greatest measurable length.The concavity depth D may be measured by identifying a shape concavityline 106 that is parallel with the shape length line 104 and tangent tothe deepest point along the concave portion 103. The concavity depth Dis the distance between the shape width line 105 a facing the concavityand the shape concavity line 106. The extent of the concavity of concaveportion 103 may be expressed as a ratio of concavity depth D to shapelength L (hereinafter, “concavity depth ratio”). Although shapes that donot have a concave portion 103 are contemplated, it may be desirablethat a bonding shape has a concave portion having a concavity depthratio between 0.00 and 0.30, more preferably between 0.00 and 0.25, andeven more preferably between 0.00 and 0.20. Again, the bond shapes andsizes impressed on the nonwoven web will reflect and correspond with thebonding shapes and sizes on the roller.

Whilst the explanation above refers to bonding protrusions and resultingconsolidated bond shapes in the web, which have bonding shape/bond shapeperimeters following “convex” and/or “concave” (impliedly, smooth)curves, it may be appreciated that the effect may be substantiallyrealized by approximating such smooth curves with chains of straightline segments. Accordingly, each of the terms “convex” and “concave”herein includes a portion of a shape perimeter formed of a chain of 5 ormore straight line segments lying on one side of a shape length line andconnected end-to-end, that is each a chord of a smooth convex or concavecurve lying on one side of the shape length line, or portion of a curvelying on one side of the shape length line that does not include aninflection point.

Without intending to be bound by theory, it is believed that calenderroller bonding protrusions having bonding shapes with one or morefeatures as described above have aerodynamic effects on air flow in andabout the nip, that cause acceleration and deceleration of air in andabout the interstices of the nonwoven fibers in a way that repositionsthe fibers, and may effect teasing or fluffing, adding loft and caliper.

Additionally, the rotational orientations of the protrusions affect theorientations of the bonding protrusions at the nip, and it is believedthat this has an impact. Bonding shapes 100 and the bonding protrusionssupporting them may be arranged along an individual shape tilt anglerelative the machine and cross directions. Without intending to be boundby theory, it is believed that the shape tilt angle should not exceed acertain amount for the bonding protrusion to have maximum beneficialeffect on air flow. Referring again to FIG. 5B, the shape tilt angleα_(T) may be expressed as the smaller angle formed by the intersectionof an axis along the machine direction 108 and the shape length line104. It is believed, that the shape and the shape tilt angle havecooperating effects on the air flow. In the case of an asymmetricbonding shape, such as the described airfoil-like shape, it is believedthat this asymmetric bonding shape is sufficient for effecting thedesired changes in air flow. However, a rotational orientation with atilt angle of more than zero may enhance the effect. With respect to abonding shape that is not asymmetric, it is believed that the shape tiltangle α_(T) provides the desired effects on air flow, such that it thenshould not be less than 1 degree and should not exceed 40 degrees, morepreferably, 30 degrees, and still more preferably, 20 degrees. It isbelieved that a shape tilt angle within this range effectively providesair flow through the nip, while at the same time, impartscross-direction vector components to air flows through the nip.Conversely, a shape tilt angle greater than 40 degrees may create toomuch of an obstruction to air flow through the nip to have a beneficialeffect, and even greater shape tilt angles combined with sufficientdensity of bonding protrusions may have the effect of creating enoughobstruction at the nip to substantially divert airflow from the nip,i.e., toward the sides of the bonding rollers, rather than through thenip. The bond shapes and rotational orientations impressed on thenonwoven web will reflect and correspond with the bonding shapes androtational orientations on the roller.

It is believed that air flows having cross-direction vector componentsflowing across or through the batt/web as it passes through and exitsthe nip may urge fibers in the cross-direction, helping add loft,caliper and/or cross direction tensile strength. It will be appreciatedthat the fibers of many nonwoven batts are laid down in the nonwoven webmanufacturing process with a general machine direction orientation orbias, which tends to result in the finished web having relativelygreater machine direction tensile strength, and relatively less crossdirection tensile strength. Thus, any process that tends to impart someadded cross-direction orientation to the fibers prior to bonding may beuseful for increasing cross direction tensile strength, bringing aboutbetter balance between machine direction tensile strength andcross-direction tensile strength, and adding loft such as byrepositioning of the fibers in the z-direction. It is believed that, forbest results, it may be even more desirable that shape tilt angle α_(T)is between 5 degrees and 15 degrees, more preferably between 8 degreesand 12 degrees, and even more preferably between 9 degrees and 11degrees, for the most beneficial effects on airflow at the line speedscontemplated herein. The rotational orientation of the bonding patternimpressed on the nonwoven web will reflect and correspond with therotational orientation of the bonding pattern on the roller.

As suggested above, in order to gain the benefit of energy from asubstantial mass of air flowing through the nip, it is also believeddesirable that a pattern of bonding protrusions not be excessivelyobstructive of air flow through the nip, nor that it remove too muchenergy from the air flow by overly slowing, or halting, and absorbingthe energy from, forward (machine-direction) momentum of air flows.Referring to FIG. 5C, a nip line 107 a along the cross direction isidentified along a pattern where the bonding shapes occupy the greatestproportion of distance along a cross direction line that can beidentified in a pattern. Thus, nip line 107 a located as shownrepresents a cross-direction line along which bonding protrusionspresented the greatest amount of obstruction that can be identified in aparticular pattern, to air flow through the nip, during the bondingprocess. A repeating series of shapes can be identified; in thisexample, the repeating series consists of the four shapes 100 a, 100 b,100 c and 100 d. Widths w₁, w₂, w₃, and w₄ of the identified shapes 100a, 100 b, 100 c, 100 d in the repeating series reflect restriction ofair flow along the nip line 107 a. Width w_(p) is the width of theentire repeating series, including the distances between the bondingshapes. The proportion of maximum restriction along the nip length forthe pattern is reflected by the ratio (w₁+w₂+w₃+w₄ . . . +w_(n))/w_(p),referred to herein as the nip airflow restriction ratio (where “w” isthe cross-direction width along the nip line 107 a of a bonding shapeperimeter, and “n” is the number of bonding shapes along nip line 107 athat make up a repeating series). In order that a bonding pattern allowsfor effective air flow through the nip in order to take advantage ofenergy of moving air, it may be desirable that the nip airflowrestriction ratio be 0.40 or less, more preferably 0.30 or less, andeven more preferably 0.25 or less. The bond shapes, rotationalorientations and density/numerosity per unit surface area of bondimpressions on the nonwoven web will reflect and correspond with thebonding shapes, rotational orientations and density/numerosity per unitsurface area of bonding protrusions on the roller, and thus, alsoreflect the airflow restriction ratio.

Referring to FIGS. 6A and 6B, an alternative bonding pattern isdepicted. The repeated bonding shape 100 and profile of the associatedbonding protrusion is a composite of two generally convex/concavesub-shapes joined or superimposed at their respective tips, in reversedorientation, to form an open “S” shape which is rotationally symmetricabout this juncture of the component sub-shapes, respectively its middleinflection point. It will be appreciated, however, that the depictedrepeated “S” shape may have several of the features of the bonding shapedepicted in FIGS. 5A and 5B, described above, which are believed to bebeneficial. The depicted bonding shape 100 in FIGS. 6A and 6B has agreatest measurable length L and greatest measurable width W, measuredwith respect to shape length line 104 and shape width lines 105 a, 105b, identified in the manner described above. As set forth above, bondingshapes 100 within the scope of the present invention have an aspectratio of greatest measurable length L to greatest measurable width W ofat least 2.5, more preferably at least 2.7, and even more preferably atleast 2.8.

The depicted bonding shape in FIGS. 6A and 6B also has convex portions102 a, 102 b along its perimeter. One or both of the convex portions 102a, 102 b may have varying radii, and have camber heights CH_(A) andCH_(B). It is believed that, for maximum beneficial impact on airflow,it may be desirable that the ratio between camber height CH and thegreatest measurable length L also be 0.30 or less, more preferably 0.25or less, but greater than zero.

The depicted bonding shape also has concave portions 103 a and 103 balong its perimeter. Concavity depth Da is the distance between shapewidth line 105 a facing concavity 103 a, and shape concavity line 106 a.Concavity depth Db is the distance between shape width line 105 b facingconcavity 103 b, and shape concavity line 106 b. Although bonding shapesthat do not have a concave portion 103 a, 103 b along their perimetersare contemplated, it may be desirable that a bonding shape perimeter hasone or more concave portions such as concave portions 103 a, 103 bhaving a concavity depth ratio:Concavity depth/(L*nc)≦0.30, more preferably 0.25, and even morepreferably 0.20,where nc is the number of fully enclosed shapes that are defined byportions of the bonding shape perimeter and the shape length line, whichevidence concavities. For example, for the “S” shape shown in FIG. 6B,nc=2 because there are 2 such fully enclosed shapes 124 a and 124 b.

The shapes 100 in FIGS. 6A and 6B also may have a shape tilt angle α_(T)determined as set forth above, and within the ranges set forth. Thegeometric features of the bond shapes and pattern on the nonwoven webwill reflect and correspond with those of the shape, size, rotationalorientation, density and arrangement of the bond shapes 100.

It is also believed that arranging the bonding protrusions in a patternsuch that a relatively straight, unobstructed passageway between themexists along recessed areas 101 at the nip, at least partially along themachine direction, may have beneficial effects. Referring to FIGS. 5Aand 6A, it can be seen that each example has a cross-nip airflow line109 that can be identified, that intersects no bonding shape, andintersects a cross direction axis 107 at an angle such that it has amachine direction vector component. Cross-nip airflow line 109intersects cross direction axis 107 to form a smaller angle, identifiedherein as cross-nip airflow angle β_(A). It is believed that cross-nipairflow angle β_(A) is preferably greater than 45 degrees, morepreferably between 50 degrees and 90 degrees, and even more preferablybetween 60 degrees and 90 degrees. It is believed desirable thatcross-nip airflow line 109 should extend indefinitely withoutintersecting a bonding shape 100, but at a minimum, past at least 8 rows110 of bonding shapes 100 without intersecting a bond shape. Again,geometric features of the bond shapes and pattern on the nonwoven webwill reflect and correspond with those of the shape, size, rotationalorientation, density and arrangement of the bond shapes 100.

Another aspect of the bonding shapes and patterns depicted in, e.g.,FIGS. 5A-6B is that they may have any combination of the above-describedaspect ratios, maximum nip airflow restriction ratio (0.40 or less),shape asymmetry, shape tilt angles, and other features, and may alsoreflect use of adjacent pairs of bonding protrusions that define airpassageways through the nip that alternately narrow and widen, orconverge and diverge, in the manner of a venturi. For example, referringagain to FIGS. 5A and 6A, two adjacent bond shapes 100 a, 100 b may beidentified. Herein, “adjacent” means that at least portions of theperimeters of a pair of shapes face each other with no interveningshapes between them; and that the pair of shapes has machine-directionoverlap. The pair of shapes has machine-direction overlap if one or morecross-direction lines 107 that are tangent to and/or cross theperimeters of each of the shapes may be identified. A minimum passagewayclearance line MC may be identified connecting the perimeters of theshapes 100 a, 100 b, at the location where the shortest measurabledistance between the perimeters exists. The minimum passageway clearanceline MC will necessarily meet the perimeter of each of the adjacentshapes where line MC is normal to the perimeter, and line MC identifiesthe point of greatest constriction of an air passageway between theshapes (i.e., through the corresponding bonding protrusions) proximateand through the nip. A passageway line PL may be identified,perpendicular to the minimum passageway clearance line MC and lyingbetween the adjacent shapes 100 a, 100 b.

The minimum passageway clearance line MC crosses and identifies a“venturi passageway” if the perimeter of each of the adjacent shapes 100a, 100 b diverges away from the passageway line PL moving along theperimeter away from the minimum clearance line MC in both directions. Itcan be seen in FIGS. 5A and 6A that adjacent shapes 100 a, 100 b embodythis feature.

Without intending to be bound by theory, it is believed that suchventuri passageways have the effect of causing localized zones ofacceleration and deceleration, and increases and decreases in pressure,as well as turbulence, of air as it passes through the nip. It isbelieved that these effects serve to tease and/or fluff the fibers ofthe batt and web about the nip.

For purposes of downstream handling and manufacturing processes, it maybe desirable to ensure that no line along the machine direction existsalong the nonwoven web surface that is indefinitely long withoutintersecting a bond impression. This condition (indefinitely longmachine direction strip of web without bonds) may result in relativelylong lengths of unbonded fibers that may be prone to moving away from acutting knife in downstream machine direction web slitting operations,resulting in a poorly defined or sloppy slit edge. Additionally, suchlong, unbonded fibers may also separate from a manufactured edge or slitedge of the web (fraying), which may cause other difficulties indownstream operations. To avoid this condition, it may be desirable toimpart a pattern angle γ_(P) to the bonding pattern. Referring to FIG.6A, pattern angle γ_(P) may be expressed as the smaller angle formed bythe intersection of a line 111 connecting like points on repeating,similarly oriented shapes in columns 112, and a machine direction axis.To avoid the above-mentioned problems, it may be desirable that patternangle γ_(P) be greater than 0 degrees. A pattern angle greater than 0degrees will ensure that an indefinitely long machine direction strip ofweb without bonds will not exist. To avoid creating complications withrespect to the air flow benefits of the pattern, however, it may bedesirable to limit pattern angle γ_(P) to 4 degrees or less, morepreferably 3 degrees or less, and even more preferably 2.5 degrees orless. Again, features of the bond pattern on the nonwoven web includingpattern angle will reflect and correspond with those of the pattern andpattern angle γ_(P) on the roller.

The features described above apply to the shapes of bonding surfaces ofbonding protrusions in a pattern on a bonding roller, and it will beunderstood that these features are impressed by the roller into thenonwoven batt to form bond impressions having bond shapes and bondsthereat, to form the calender-bonded nonwoven web. As impressed into anonwoven web, the bonding shapes are reflected as bond shapes, and areidentifiable, and measurable in the web, in laminates that include suchnonwoven web as a composite layer, and in composite products made fromsuch nonwoven web and/or such laminates.

An additional aspect that it believed important is bonding area of aroller, reflected in bond area on the web. Imagining a pattern ofbonding surfaces having shapes reflected in FIGS. 5A and 6A impressed ona surface of a nonwoven web, bonding area and bond area is the areaoccupied by the bonding shapes on the roller and bond shapes impressedon the surface of the web. In the field of nonwoven web manufacturing,bonding area is often expressed as a percentage, calculated as:

${{Bonding}\mspace{14mu}{Area}\mspace{14mu}\%} = {\quad{\left\lbrack \frac{\left( {{bonding}\mspace{14mu}{area}\mspace{14mu}{within}\mspace{14mu} a\mspace{14mu}{surface}\mspace{14mu}{area}\mspace{14mu}{unit}} \right)}{\left( {{total}\mspace{14mu}{surface}\mspace{14mu}{area}\mspace{14mu}{of}\mspace{14mu}{the}\mspace{14mu}{surface}\mspace{14mu}{area}\mspace{14mu}{unit}} \right)} \right\rbrack \times 100\%}}$

The bonding area reflects the combination of bonding protrusion density(number of bonding protrusions per unit surface area) and averagesurface area of the bonding shapes 100 in the unit surface area. Thus,increasing the number of bonding protrusions and/or increasing thesurface area of the individual bond shapes 100 increases the bondingarea, and vice versa. It is believed that bonding area has an impact onthe entrainment of air as well as the proportion of entrained aircarried toward the nip, which will pass through the nip. If bonding areais relatively greater, this means that more and/or larger bondingprotrusions are present at the nip point at any time to obstruct airflow through the nip; conversely, if bonding area is relatively less,this means that fewer and/or smaller bonding protrusions are present atthe nip point at any time to obstruct air flow through the nip. Bondarea has another effect as well. Increasing bond area increases thenumber and proportion of the fibers in the nonwoven web that are bondedtogether, and vice versa. Within a certain range of bond area, tensilestrength of the nonwoven web in the machine and/or cross directions maybe increased by increasing the bond area. However, bending stiffness ofthe nonwoven web may be correspondingly increased, and loftdecreased—compromising the soft feel and/or appearance of the nonwoven.In order to best realize the benefits of air flow, air compression andchanneling believed to be occurring through use of the bond shapesdescribed herein, enhancing loft, while still imparting satisfactorytensile properties to the web, it is believed that bonding area shouldbe in the range of 4.0% and 18%, more preferably between 6% and 16%, andeven more preferably between about 8% and 14%. At the line speedscontemplated herein, and relative to the bonding area, the averagesurface area per bonding shape affects bonding area and bondingprotrusion density. It is believed desirable that the average bondingshape 100 surface area be in the range of 0.3 mm² and 10 mm².Correspondingly, it is believed desirable that the density of thebonding protrusions, and correspondingly, the impressed bond shapes, bebetween 0.4 bonding protrusions/cm² for bonding shape/bond shape area of10 mm² at 4% bonding area and 60 bonding protrusions/cm² for bondingshape/bond shape area of 0.3 mm² at 18% bonding area Similarcalculations of bonding protrusion density and average bond shapesurface area to arrive at the bond areas in the ranges set forth above,will be appreciated. The surface area and density of bond shapesimpressed on the nonwoven web will reflect and correspond with those ofthe bonding shapes, and thus, the bond area on the web will reflect andcorrespond with the bonding area on the roller as well.

It is also believed that the speed of travel of the batt toward thebonding nip (batt line speed) is important. It will be appreciated that,if the batt line speed is too slow, air mass entrained by the batt as itapproaches the nip will not have sufficient linear momentum to maintaina large enough zone of sufficiently elevated air pressure at the entryside effective to ensure that substantial air mass is urged through thenip, rather than being merely urged around the nip and the rollers alongalternate pathways. Accordingly, it is believed that line speed at whichthe batt is conveyed toward the nip should be equal to or greater than300 meters/minute, more preferably, equal to or greater than 600meters/minute, and even more preferably, equal to or greater than 800meters/minute.

It is believed that use of a calender roller having bonding patterns andbonding shapes as described herein take advantage of air flows resultingfrom entrainment of air along a moving nonwoven batt and calenderrollers, and air compression, that occur during calender-bonding, in away that causes the resulting nonwoven web to have enhanced loft and asoft feel. It is believed also that the bonding shapes need not be allof like kind or rotational orientation, but rather, that suitablecombinations of differing shapes including bonding shapes havingfeatures as described herein, and optionally, in combination with othershapes, may be used and included. Employment of the described featuresmay reduce or eliminate a need for other loft enhancement processes,such as hydroengorgement or hydroentanglement—which may save costs ofadditional equipment and operation.

In addition to the above-described features and processes that may beuseful for producing a nonwoven web with relatively enhanced loft, otherfeatures and processes may be employed. Processes such as carding,hydroengorgement, hydroentanglement and bi-component spunbond productionmay be effective for producing relatively low-density nonwoven webmaterials. Hydroentanglement and/or hydroengorgement are described in,for example, U.S. Pat. Nos. 6,632,385, 6,803,103, and 7,858,544, andU.S. Pat. App. Pub. No. 2012/0094567. Hydroengorgement in combinationwith other processes and features is disclosed in, e.g., U.S.application Ser. No. 13/213,177. Features and processes for productionof bi-component, crimped fibers with enhanced loft are described in, forexample, U.S. Pat. No. 7,789,870; U.S. Pat. Pub. No. 2007/0275622;European Pat. App. No. EP 1 369 518 A1; and PCT App. No. WO 2007/097467.

In addition to relatively low density (i.e., high loft) attributes for anonwoven, it is believed from consumer research that relatively lowsurface friction (i.e., a relatively smooth, gliding or slippery feel)can enhance tactile perceptions of softness. Any of several combinationsof materials and processes may be employed to produce a nonwoven havinga relatively slippery feel, i.e., relatively low coefficients offriction along its surface. One approach includes forming the nonwovenfrom fibers composed partially or entirely of polyethylene. Relative toother materials deemed useful and economically practically for themanufacture of nonwovens of the types contemplated herein (such as, forexample, polypropylene), polyethylene provides a relatively slipperyfeel (relatively low coefficients of friction). For example, abicomponent fiber having a polyethylene component in a side-by-sidearrangement (polyethylene forms portions of outer surfaces of fibers),or even in a core-sheath arrangement (polyethylene forms substantiallyall of outer surfaces of fibers, may be deemed suitable. Anotherapproach may involve coating the nonwoven surfaces or fibers thereofwith a silicon-based topical coating, to impart a slippery feel.

As noted, some types of disposable absorbent articles such as diapersmay have absorbent cores that contain particles of absorbent polymermaterial, which serves to absorb and store liquid exudates. In somedesigns, the absorbent cores also include cellulosic fiber material(airfelt), also included to help absorb and store liquid exudates, butalso included to provide a matrix in which absorbent polymer particlesare dispersed and distributed, so as to prevent gel blocking Other coredesigns, however, do not rely upon, and may have portions that do notinclude, cellulosic fiber material. For example, some core designs mayreply upon adhesive to retain the absorbent polymer particles indispersed and distributed locations along the core, and thus, such coresmay have substantial portions along their lengths in which relativelylittle or no airfelt is included.

Disposable absorbent articles such as diapers having cores withabsorbent polymer particles but a relatively low amount of cellulosefibers, or diapers with absorbent cores that are substantiallyairfelt-free along portions of their lengths, may in some circumstancesbe less likely to be perceived as relatively “soft,” all other factorsbeing equal. Absorbent cores of designs that include substantialquantities of cellulosic fiber for fluid absorption and/or storage tendto be bulkier and thicker, and the cellulose fiber batt or wad tends tobe relatively highly compressible in the hands. These attributes maycombine to promote perceptions of softness.

Conversely, absorbent cores of designs that rely substantially only onparticulate absorbent polymer materials for fluid absorption and/orstorage, with comparatively low or substantially eliminated quantitiesof cellulosic fibers along some or all of their lengths, tend to bethinner and relatively less compressible in the hands. These attributesmay combine to reduce perceptions of softness. It is believed, also,that in absorbent cores having particulate absorbent polymer materialsand relatively low quantities of cellulosic fibers along some or all oftheir lengths, the relatively hard individual particles, or relativelyhard deposits of particles, may be felt by the hands through theenveloping layers of the article containing the particles, thusimparting a tactile granular feel that is believed to negatively impactsoftness perceptions. The granular feel results from concentrations ofpressure perceivable upon squeezing or similar manipulation, localizedover the individual particles or deposits. In other words, theindividual particles or deposits create tactile “pressure points.”

Similarly, the presence of elastic members such as elastic strandsbetween nonwoven web materials respectively forming the outermost andinnermost layers of the diaper (including but not limited to thetopsheet and backsheet), included to form, e.g., leg cuffs(longitudinally-oriented strands), elasticized waistbands(laterally-oriented strands), or elasticized side panels(laterally-oriented strands), may create tactile pressure points orridges giving a ribbed or ridged feel to the diaper.

Through research it has been learned that some consumers, when asked toevaluate the softness of samples of disposable diapers provided to them,naturally tend to conduct their evaluations in part by gripping thediapers between the thumb and one or more of the fingers, for example,with the thumb over and contacting the topsheet 18 and the finger(s)beneath and contacting the backsheet 20 (with reference to FIG. 2A) andsqueezing them and rubbing them between thumb and finger(s). For diapershaving absorbent cores having particulate absorbent polymer materialsand relatively low quantities of cellulosic fibers, and for diapershaving elastic strands sandwiched between outermost and innermostlayers, this manner of evaluation may result in the consumer quicklynoticing the pressure points.

It has been discovered, however, that selection of component materialsfor topsheet and backsheet having particular attributes in combinationmay impact the manner in which the softness of the diaper structure isperceived. It has been found that selection of particular combinationsof attributes can reduce or mask the pressure points, or make them lesslikely to be noticed by consumers.

As noted, the topsheet and the outermost layer of the backsheet may berespectively formed of nonwoven web materials. In one particular, it isbelieved that these nonwoven web materials may be imparted with aminimum basis weight, and a minimum loft or caliper per unit basisweight, or, expressed differently, a maximum density, to effectivelypromote or maintain satisfactory impressions of softness. In anotherparticular, these materials may be imparted with a minimum compressionloft (as determined by the Compression Loft measurement method set forthbelow), which reflects the relative loftiness of the material and,independent of its density. If each of these nonwoven web materialssatisfy such criteria, they may be sufficiently effective to diffusepressure away from pressure points over particles of absorbent polymer,or otherwise make the pressure points less noticeable, when the diaperis handled.

For these reasons, it may be desired that the nonwoven web materialsforming the topsheet and the outer layer of the backsheet have acombined basis weight of at least 30 gsm, more preferably at least 40gsm, and still more preferably at least 50 gsm. In combination, it maybe desired that each of the nonwoven web materials have a pre-conversiondensity no greater than 65 kg/m³, and more preferably no greater than 55kg/m³, where “pre-conversion density” for a particular nonwoven webmaterial is determined at the point in the manufacturing process atwhich the material is first unwound from its supply roll after havingbeen manufactured, gathered and stored on the roll. Also, in combinationwith the above-specified density and basis weight, or in anothercombination with basis weight, it may be desired that each of thenonwoven web materials has a compression loft of at least 30%, morepreferably at least 50%, and even more preferably at least 70%.

It will be appreciated that loft can be increased, and thus densitydecreased, by use of any of the materials, and by any of the variousprocesses and techniques effective for imparting, preserving orenhancing loft of a nonwoven described herein, or described in prior artreferences cited and incorporated by reference herein.

While increasing basis weights of these respective nonwoven webmaterials (which may generally tend to increase caliper, all otherfactors being equal) may be effective to diffuse pressure away fromtactile pressure points, and it may be intuitive that increasing basisweight without constraint may be particularly effective, themanufacturer is always under cost constraints. Since increasing basisweight of any particular component web material will add material cost,increasing basis weight to a degree deemed most satisfactory fordiffusing pressure away from pressure points may be unacceptably costly.

It is believed, however, that another cost-mitigating strategy may beeffective. It is believed that if one of the nonwoven web materialsforming the topsheet and outer layer of the backsheet is significantlydifferent from the other with respect to certain attributes, this canhave a negative impact on softness perceptions. It is believed thatcertain attributes of a nonwoven are pressure-diffusing attributes,meaning that they may serve to diffuse the pressure and resultingtactile sensation created by a pressure point over a particular ofabsorbent polymer material. It is believed that attributes such as butnot necessarily limited to compression loft, density, basis weight, andfrictional properties (i.e., the tactile “slipperiness” of the material)are pressure-diffusing attributes. Without intending to be bound bytheory, it is believed that a substantial imbalance between pressurediffusing attributes of the respective nonwoven web materials formingthe topsheet and outer layer of the backsheet may have the effect ofcausing the observer to be more likely to notice pressure points on theside of the article (i.e., the wearer-facing topsheet side or theoutward-facing backsheet side) formed of the nonwoven web material withthe lesser of the pressure-diffusing attributes. It is believed thatsuch an imbalance has an exacerbating effect particularly when, forexample, the respective nonwovens are of relatively low basis weights.

Conversely, if these materials are selected so as to be sufficientlysimilar or relatively balanced with respect to certain pressurediffusing attributes, this can have a positive impact on softnessperceptions. It is believed, further, that such balance can have asynergistic effect when combined with pressure diffusing attributes,such that a combination of such balance with pressure diffusingattributes of the nonwoven web materials can allow use of nonwovenmaterials of relatively lower basis weights than might otherwise beexpected, while still being sufficient to effectively mask tactilepressure points or make them less noticeable to the consumer.

Thus, it may be desired that, in combination with the combined basisweight of the respective nonwoven web materials forming the topsheet andthe outer layer of the backsheet, the ratio of one or any combination ofthe basis weight, density and compression loft, of the nonwoven webmaterial forming the topsheet and the nonwoven web material forming theouter layer of the backsheet be from 30/70 to 70/30, more preferablyfrom 40/60 to 60/40, and even more preferably from 45/55 to 55/45. Itmay also be desired that the respective materials have respectivecoefficients of static and kinetic friction no greater than certainamounts. Additionally, it may be desired that the respectivecoefficients of friction of the respective nonwoven web materials arewithin 30, more preferably 20, and still more preferably 10 percent ofeach other (where the percent differential is the ratio of thedifference between the respective coefficients divided by the smaller ofthe two, multiplied by 100%).

Imparting one or more of such balances of attributes in selection ofthese respective materials may enable usage of nonwoven web materialshaving combined basis weights (for nonwoven web materials formingtopsheet and outer layer of backsheet) no more than 75 gsm, morepreferably no more than 65 gsm, and even more preferably no more than 60gsm, providing for effective masking and/or reduced perception oftactile pressure points while enabling observation of cost constraintson basis weight.

Examples of Nonwoven Web Materials for Topsheet and Backsheet OuterLayer

In following examples for the manufacture of nonwoven webs, if it is notdefined differently, the batt was produced from 3 following spunbondbeams on REICOFIL 4 technology, using the four different bondingpatterns indicated:

Pattern “Wing-Shape” (as Depicted in FIG. 5)

-   -   Bonding area percentage=12.4%    -   Bonding protrusions/cm²=3.1    -   Angle α_(T)=10°    -   Angle β_(A)=90°    -   Angle γ_(P)=1°    -   L=6.2 mm    -   W=1.7 mm    -   D=0.9 mm    -   CH=1.4 mm    -   Distance between beginning of repeating shapes in columns=8 mm    -   Distance between beginning of repeating shapes in rows=8 mm    -   Bonding protrusion height=0.65 mm        Pattern “S-Shape” (as Depicted in FIG. 6)    -   Bonding area percentage=12.9%    -   Bonding protrusions/cm²=1.5    -   Angle α_(T)=10°    -   Angle β_(A)=60°    -   Angle γ_(P)=1°    -   L=12.2 mm    -   W=4.0 mm    -   D_(A)=3.1 mm    -   D_(B)=3.1 mm    -   CH_(A)=1.9 mm    -   CH_(B)=2.1 mm    -   Distance between beginning of repeating shapes in columns=11.4        mm    -   Distance between beginning of repeating shapes in rows=6.0 mm    -   Bonding protrusion height=0.65 mm        Pattern “S-Shape v2” According to the Invention (FIG. 7)    -   Bonding area percentage=13%    -   Bonding protrusions/cm²=2.4    -   Angle α_(T)=10°    -   Angle β_(A)=63°    -   Angle γ_(P)=1°    -   L=9.2 mm    -   W=3.0 mm    -   D_(A)=2.3 mm    -   D_(B)=2.3 mm    -   CH_(A)=1.3 mm    -   CH_(B)=1.6 mm    -   Distance between beginning of repeating shapes in columns        (DRC)=8.8 mm    -   Distance between beginning of repeating shapes in rows        (DRR)=4.65 mm    -   Bonding protrusion height=0.75 mm        Comparative Pattern “Standard Bulky” Described in Patent        Application WO 2009/021473 (Depicted in FIG. 4A).    -   Bonding area percentage=14.0%    -   Bonding protrusions/cm²=9    -   Angle α_(T)=0°    -   Angle β_(A1)=90°    -   Angle β_(A2)=55°    -   Angle γ_(P)=0°    -   L=3.4 mm    -   W=0.4 mm    -   D=0 mm    -   CH=0.2 mm    -   Distance between beginning of repeating shapes in columns=5.6 mm    -   Distance between beginning of repeating shapes in rows=2.0 mm    -   Bonding protrusion height=0.7 mm        Comparative Pattern “Standard”—(Oval Shape, Depicted FIGS. 4B,        4C)    -   Bonding area percentage=18.1%    -   Bonding protrusions/cm²=49.9    -   Angle α_(T)=60°    -   Angle β_(A)—does not exist    -   Angle γ_(P)=0°    -   L=0.9 mm    -   W=0.5 mm    -   D—does not exist    -   CH=0.3 mm    -   Distance between beginning of repeating shapes in columns=1.5 mm    -   Distance between beginning of repeating shapes in rows=2.6 mm    -   Bonding protrusion height=0.6 mm

Certain parameter and test results for the examples are summarized inTable 1 herein below.

Example 1—Comparative Standard Bulky

The 12 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μm(1.5 to 2.5 den) are produced and subsequently collected on a movingbelt. To increase strength a patterned calender is used consisting of apair of heated rollers, where one roller has raised comparative pattern“Standard bulky” (FIG. 4A). The temperature of the calender rollers(smooth roller/patterned roller) is 165° C./168° C. and the pressure is75 N/mm.

Example 2—Comparative Standard Bulky

A 14 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised comparative pattern “Standardbulky” (FIG. 4A). The temperature of the calender rollers (smoothroller/patterned roller) is 165° C./168° C. and the pressure is 75 N/mm.

Example 3—Comparative Standard Bulky

A 15 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised comparative pattern “Standardbulky” (FIG. 4A). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

Example 4—Comparative Standard Bulky

A 17 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised comparative pattern “Standardbulky” (FIG. 4A). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

Example 5—Comparative Standard

A 15 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised comparative pattern “Standard”(FIG. 4B). The temperature of the calender rollers (smoothroller/patterned roller) is 170° C./173° C. and the pressure is 95 N/mm.

Example 6—Comparative Standard

A 17 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised comparative pattern “Standard”(FIG. 4B). The temperature of the calender rollers (smoothroller/patterned roller) is 170° C./173° C. and the pressure is 95 N/mm.

Example 7—Comparative Standard

A 15 gsm spunmelt type nonwoven batt, produced using a continuous onlineprocess from polypropylene (HH 450 FB from Borelais) and polylactic acid(Ingeo 6202D from NatureWorks), where first the bicomponent core/sheathtype filaments are produced, where the core representing 80% is frompolylactic acid and the sheath is from polypropylene. The individualfilaments a fibre diameter of 18-40 μm are collected on a moving belt.The batt was produced on REICOFIL 3 technology from 1 beam.

To increase strength a patterned calender is used, that consist of apair of heated rollers, where one roller has raised comparative pattern“Standard” (FIG. 4B). The temperature of the calender rollers (smoothroller/patterned roller) is 140° C./140° C. and the pressure is 75 N/mm.

Example 8—Comparative Standard

The 15 gsm spunmelt type nonwoven batt produced online in a continuousprocess from a mixture of polypropylene (Mosten NB425 from Unipetrol)and copolymer (Vistamaxx 6102 from Exxon) in the weight ratio 81:19,where monocomponent polypropylene filaments with a fibre diameter of20-40 μm are produced and subsequently collected on a moving belt. Thebatt was produced on REICOFIL 3 technology from 2 beams.

To increase strength a patterned calender is used consisting of a pairof heated rollers, where one roller has raised comparative pattern“Standard” (FIG. 4B). The temperature of the calender rollers (smoothroller/patterned roller) is 145° C./145° C. and the pressure is 75 N/mm.

Example 9—“S” Shape

A 12 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “S-shape” according to theinvention (FIG. 6). The temperature of the calender rollers (smoothroller/patterned roller) is 165° C./168° C. and the pressure is 75 N/mm.

Example 10—“S” Shape

A 14 gsm spunmelt type nonwoven batt produced online in a continuousprocess from a mixture of polypropylene (Mosten NB425 from Unipetrol)and color masterbatch (Sanylene white PPRC 70 from Clariant) in theweight ratio 99.5:0.5, where monocomponent polypropylene filaments witha fibre diameter of 18-30 μm are produced and subsequently collected ona moving belt. To increase strength a patterned calender is usedconsisting of a pair of heated rollers, where one roller has raisedpattern “S-shape” according to the invention (FIG. 6). The temperatureof the calender rollers (smooth roller/patterned roller) is 165° C./168°C. and the pressure is 75 N/mm.

Example 11—“S” Shape

A 15 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “S-shape” according to theinvention (FIG. 6). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

Example 12—“S” Shape

A 17 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “S-shape” according to theinvention (FIG. 6). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

The strengthened nonwoven web is then subsequently impregnated with ahydrophilic surfactant (Silastol PHP 90 from Schill and Seilacher) usinga dip roller (kiss-roll) and dried. The extra weight of the surfactantin dry form is approximately 0.4%.

Example 13—“S” Shape

A 17 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “S-shape” according to theinvention (FIG. 6). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

Example 14—“Wing” Shape

A 12 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “wing-shape” according tothe invention (FIG. 5). The temperature of the calender rollers (smoothroller/patterned roller) is 165° C./168° C. and the pressure is 75 N/mm.

Example 15—“Wing” Shape

A 14 gsm spunmelt type nonwoven batt produced online in a continuousprocess from a mixture of polypropylene (Mosten NB425 from Unipetrol)and color masterbatch (CC10031739BG green from PolyOne) in the weightratio 99.3:0.7, where monocomponent polypropylene filaments with a fibrediameter of 18-30 μm are produced and subsequently collected on a movingbelt. To increase strength a patterned calender is used consisting of apair of heated rollers, where one roller has raised pattern “S-shape”according to the invention (FIG. 5). The temperature of the calenderrollers (smooth roller/patterned roller) is 165° C./168° C. and thepressure is 75 N/mm.

Example 16—“Wing” Shape

A 15 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “wing-shape” according tothe invention (FIG. 5). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

Example 17—“Wing” Shape

A 17 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “wing-shape” according tothe invention (FIG. 5). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

The strengthened nonwoven web is then subsequently impregnated with ahydrophilic surfactant (Silastol PHP 90 from Schill and Seilacher) usinga dip roller (kiss-roll) and dried. The extra weight of the surfactantin dry form is approximately 0.4%.

Example 18—“Wing” Shape

A 17 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 18-30 μmare produced and subsequently collected on a moving belt. To increasestrength a patterned calender is used consisting of a pair of heatedrollers, where one roller has raised pattern “wing-shape” according tothe invention (FIG. 5). The temperature of the calender rollers (smoothroller/patterned roller) is 168° C./171° C. and the pressure is 75 N/mm.

Example 19—“Wing” Shape

A 15 gsm spunmelt type nonwoven batt, produced using a continuous onlineprocess from polypropylene (Mosten NB425 from Unipetrol) andpolyethylene (Liten LS87 from Unipetrol), where first the bicomponentcore/sheath type filaments are produced, where the core representing 50%is from polypropylene and the sheath is from polyethylene. Theindividual filaments with a fibre diameter of 18-40 μm are collected ona moving belt.

To increase strength a patterned calender is used, that consist of apair of heated rollers, where one roller has raised pattern “wing-shape”according to the invention (FIG. 5). The temperature of the calenderrollers (smooth roller/patterned roller) is 154° C./154° C. and thepressure is 75 N/mm.

Example 20—“S—Shape v2”

A 25 gsm spunmelt type nonwoven batt, produced using a continuous onlineprocess from polypropylene (Mosten NB425 from Unipetrol) andpolyethylene (Liten LS87 from Unipetrol), where first the bicomponentside/side type filaments are produced, where the one side representing50% is from polyethylene and the second side is from polypropylene. Theindividual filaments with a fibre diameter of 15-25 μm are collected ona moving belt. The batt was produced from two beams REICOFIL 3technology.

To increase strength a patterned calender is used, that consist of apair of heated rollers, where one roller has raised pattern “S-shape v2”(FIG. 7). The temperature of the calender rollers (smoothroller/patterned roller) is 152° C./142° C. and the pressure is 60 N/mm.

Example 21—“S—Shape v2”

A 15 gsm spunmelt type nonwoven batt produced online in a continuousprocess from polypropylene (Mosten NB425 from Unipetrol), wheremonocomponent polypropylene filaments with a fibre diameter of 15-25 μmare produced and subsequently collected on a moving belt. The batt wasproduced from two beams on REICOFIL 3 technology.

To increase strength a patterned calender is used consisting of a pairof heated rollers, where one roller has raised pattern “S-shape v2”according to the invention (FIG. 7). The temperature of the calenderrollers (smooth roller/patterned roller) is 150° C./145° C. and thepressure is 70 N/mm.

Example 22—“S—Shape v2”

A 25 gsm spunmelt type nonwoven batt, produced using a continuous onlineprocess from polypropylene (Mosten NB425 from Unipetrol) and copolymer(Vistamaxx 6202 from Exxon) in the weight ratio 84:16 where first themonocomponent type filaments are produced. The individual filaments awith a fibre diameter of 15-25 μm are collected on a moving belt. Thebatt was produced from two beams on REICOFIL 3 technology.

To increase strength a patterned calender is used, that consist of apair of heated rollers, where one roller has raised pattern “S-shape v2”(FIG. 7). The temperature of the calender rollers (smoothroller/patterned roller) is 158° C./155° C. and the pressure is 70 N/mm.

TABLE 1 Tensile Strike strength through Modified Handle O MD/CD timethickness Density meter - MD ratio (STT) Mes. unit Pattern NW mm kg/m³mN — S Example 1 Comparative 12 gsm PP-SSS 0.21 57.1 36.0 3.07 >20Example 2 standard 14 gsm PP-SSS 0.23 60.9 40.0 2.64 >20 Example 3 bulky15 gsm PP-SSS 0.24 62.5 46.6 2.50 >20 Example 4 17 gsm PP-SSS 0.26 65.461.0 2.51 >20 Example 5 Comparative 15 gsm PP-SSS 0.17 88.2 48.0 2.0 >20Example 6 standard 17 gsm PP-SSS 0.20 85.0 64.0 2.0 >20 Example 7 15 gsmBICO 0.19 79.0 61.0 1.6 >20 PLA/PP-S Example 8 15 gsm mono 0.20 75.021.2 2.3 >20 PP + copolymer-SS Example 9 “S” shape 12 gsm PP-SSS 0.2352.2 33.8 2.40 >20 Example 10 14 gsm PP-SSS 0.26 53.8 36.5 2.14 >20Example 11 15 gsm PP-SSS 0.27 55.6 41.9 2.08 >20 Example 12 17 gsmPP-SSS 0.29 58.6 53.9 1.99 3.3 hydrophilic Example 13 17 gsm PP-SSS 0.2958.6 53.9 1.99 >20 Example 14 “wing” shape 12 gsm PP-SSS 0.22 54.5 30.42.76 >20 Example 15 14 gsm PP-SSS 0.25 56.0 34.6 2.26 >20 Example 16 15gsm PP-SSS 0.26 57.7 41.6 2.21 >20 Example 17 17 gsm PP-SSS 0.29 58.646.0 2.21 3.2 hydrophilic Example 18 17 gsm PP-SSS 0.29 58.6 46.72.21 >20 Example 19 “wing” shape 15 gsm BICO 0.28 53.6 30.2 2.11 >20PP/PE SSS Example 20 “S” shape v2 25 gsm BICO 0.39 69.4 53.0 1.90 >20PP/PE side/side-SS Example 21 “S” shape v2 15 gsm PP-SS 0.29 53.6 44.11.81 >20 Example 22 “S” shape v2 25 gsm PP + 0.37 74.0 56.3 1.93 >20copolymer-SSTest/Measurement Methods

Basis Weight

The “basis weight” of a nonwoven web is measured according to theEuropean standard test EN ISO 9073-1:1989 (conforms to WSP 130.1). Thereare 10 nonwoven web layers used for measurement, sample size 10×10 cm².

Thickness

The “thickness” of a nonwoven web is measured according to the Europeanstandard test EN ISO 9073-2:1996 (conforms to WSP 120.6) with followingmodification: the overall weight of upper arm of the machine includingadded weight is 130 g.

MD/CD Ratio

The “MD/CD ratio” is the ratio of material's tensile strength at peak inthe MD and CD direction. Both were measured according to the EDANAstandard method WSP 110.4-2005, where sample width is 50 mm, jawdistance is 100 mm, speed 100 mm/min and preload 0.1N.MD/CD ratio=tensile strength at peak in MD[N/5 cm]/tensile strength atpeak in CD[N/5 cm]

Softness

The “softness” of a nonwoven web may be measured using to the“Handle-O-Meter” test. The test used herein is the INDA IST 90.3-01. Thelower the value, the softer is the web.

Density

The “density” is the ratio of basis weight and thickness and indicatesthe bulkiness and fluffiness of the product, which are importantqualities of the nonwoven web according to the invention. The lower thevalue, the bulkier is the web.Density[kg/m³]=basis weight[g/m²]/thickness[mm].

Hydrophilic Properties

The “hydrophilic properties” of a nonwoven web may be measured using the“Strike Through Time” test. The test used herein is the EDANA standardtest WSP 70.3-2005 The lower the value, the more hydrophilic is the web.

Opacity

The opacity of a material is the degree to which light is blocked bythat material. A higher opacity value indicates a higher degree of lightblock by the material. Opacity may be measured using a 0°illumination/45° detection, circumferential optical geometry,spectrophotometer with a computer interface such as the HunterLabLabScan XE running Universal Software (available from Hunter AssociatesLaboratory Inc., Reston, Va.). Instrument calibration and measurementsare made using the standard white and black calibration plates providedby the vendor. All testing is performed in a room maintained at about23±2° C. and about 50±2% relative humidity.

Configure the spectrophotometer for the XYZ color scale, D65 illuminant,10° standard observer, with UV filter set to nominal. Standardize theinstrument according to the manufacturer's procedures using the 1.20inch port size and 1.00 inch area view. After calibration, set thesoftware to the Y opacity procedure.

To obtain the specimen, lay the sample flat on a bench, body facingsurface downward, and measure the total longitudinal length of thearticle. Note a site 33% of the total length from the front waist of thearticle along the longitudinal axis and a second site, 33% of the totallength from the back waist of the article. Carefully remove thebacksheet laminate, consisting of both the film and nonwoven web, fromthe garment-facing side of the article. A cryogenic spray, such asCyto-Freeze (obtained from Control Company, Houston, Tex.), may be usedto separate the backsheet laminate from the article. Cut a piece 50.8 mmby 50.8 mm centered at each site identified above. Precondition samplesat about 23° C.±2 C.° and about 50%±2% relative humidity for 2 hoursprior to testing.

Place the specimen over the measurement port. The specimen shouldcompletely cover the port with the surface corresponding to thegarment-facing surface of the article directed toward the port. Coverthe specimen with the white standard plate. Take a reading, then removethe white tile and replace it with black standard tile without movingthe specimen. Obtain a second reading, and calculate the opacity asfollows:Opacity=Y value_((black backing)) /Y value_((white backing))×100

A total of five identical articles are analyzed and their opacityresults recorded. Calculate and report the average opacity and standarddeviation for the 10 backsheet laminate measurements to the nearest0.01%.

Using the same specimens as above, remove the nonwoven web from the filmlayer for analysis. The cryogenic spray can once again be employed.Precondition samples at about 23° C.±2 C.° and about 50%±2% relativehumidity for 2 hours prior to testing. In like fashion, analyze thenonwoven web layer following the above procedure. Calculate and reportthe average opacity and standard deviation for the 10 nonwoven webmeasurements to the nearest 0.01%.

Bond Shape Measurement Methods

Area, distance and angle measurements are performed on images generatedusing a flat bed scanner capable of scanning at a resolution of at least4800 dpi in reflectance mode (a suitable scanner is the Epson PerfectionV750 Pro, Epson, USA). Measurements are performed using ImageJ software(Version 1.43u, National Institutes of Health, USA) and calibratedagainst a ruler certified by NIST.

Samples of the subject nonwoven web that are 80 mm by 80 mm are used.Precondition the samples at about 23° C.±2 C.° and about 50%±2% relativehumidity for 2 hours prior to testing. Identify the machine direction ofthe nonwoven web and draw a fine line on each sample along the machinedirection to enable scanned images to be aligned.

Place the sample to be measured on the flat bed scanner, with thesurface bearing the bond impressions or bond shapes facing downward,with the ruler directly adjacent. Placement is such that the dimensioncorresponding to the machine direction of the nonwoven is parallel tothe ruler. A black backing is placed over the specimen and the lid tothe scanner is closed. Acquire an image composed of the nonwoven andruler at 4800 dpi in reflectance mode in 8 bit grayscale and save thefile. Open the image file in ImageJ and perform a linear calibrationusing the imaged ruler.

Unless otherwise stated, dimensional and area measurements are made intriplicate, of three similar bond shapes on each sample for 6 similarsamples. The 18 values are averaged and reported.

Not intending to be bound by the specific examples, FIGS. 5A through 6Bare referenced to illustrate the following dimension measurements. Thesemeasurement methods are equally applicable to other bond shapes andrepeating bond patterns.

Greatest Measurable Length (L)

The bond shape has a perimeter and a greatest measurable length.Identify a shape length line (e.g. line 104) which intersects the twofarthest-most points along the perimeter. Draw a shape length linethrough these points. With the measuring tool, measure the length alongthe line segment between these points to the nearest 0.001 mm. Forexample, the greatest measurable lengths in FIGS. 5B and 6B areindicated at L, respectively measured along shape length lines 104.

Greatest Measurable Width (W)

Relative the greatest measurable length, the bond shape has a greatestmeasurable width measured along a direction perpendicular to the shapelength line. Draw two lines, parallel to the shape length line, andtangent to the bond shape perimeter at one or more outermost points thatare most distant from the shape length line. These are the shape widthlines. With the measuring tool, measure the greatest measurable widthbetween the shape width lines along a line segment perpendicular to theshape length line to the nearest 0.001 mm. For example, the greatestmeasurable widths in FIGS. 5B and 6B are indicated at W, respectivelymeasured between lines 105 a and 105 b perpendicular to shape lengthlines 104.

Minimum Passageway Clearance

Any two adjacent bond shapes have minimum passageway clearance, definedas the smallest measurable distance therebetween. Identify the twoparallel lines, one tangent to the perimeter of the first shape where itappears closest to the second shape, and one tangent to the perimeter ofthe second shape where it appears closest to the first shape, that liecloser together than any other such parallel lines that can beidentified. The minimum passageway clearance is the distance between theidentified parallel lines, measured along a line perpendicular to them.

Camber Height (CH)

If the bond shape has a perimeter with a convex portion, the convexportion has a maximum distance from the shape length line, referred toherein as the camber height. Draw a line that is tangent to the convexportion, and parallel to the shape length line. With the measuring tool,measure the distance between width between this tangent line and theshape length line along a direction perpendicular to the shape lengthline, to the nearest 0.001 mm. For example, the camber heights of theconvex portions in FIGS. 5B and 6B are CH, and CH_(a) and CH_(b),respectively.

Concavity Depth (D)

If the bond shape has a perimeter with a concave portion, the concaveportion has a maximum distance from the facing shape width line. Draw aline that is tangent to the deepest point along the concave portion ofthe profile, and parallel to the shape length line. This is the shapeconcavity line. With the measuring tool, measure the distance betweenshape concavity line and the shape length line along a directionperpendicular to the shape length line to the nearest 0.001 mm. Forexample, the concavity depths of the concave portions in FIGS. 5B and 6Bare D, and D_(a) and D_(b), respectively.

Shape Tilt Angle (α_(T))

The bond shape is rotationally oriented relative the machine directionby shape tilt angle α_(T). Draw a line in the cross direction,intersecting the shape length line. Draw a line in the machine directionperpendicular to the cross direction line, intersecting both the crossdirection line and the shape length line. Using the angle measuringtool, measure the smaller angle between the machine direction line andthe shape length line to the nearest 0.1 degree. For example, the anglebetween lines 108 and 104 in FIG. 5B is the shape tilt angle α_(T).

Pattern Tilt Angle (γ_(P))

The bond shapes may form a pattern that is tilted from the machinedirection by the angle γ_(P). Identify a repeating series of bond shapesin a column. Draw a column line that is tangent on one side at the sameposition on two similar shapes having similar rotational orientations inthe column. Draw a line in the machine direction that intersects thiscolumn line at an angle, if such a line exists. With the angle measuringtool, measure the smaller angle between the column line and the machinedirection line to the nearest 0.1 degree.

Airflow Restriction Ratio

The bond shapes form a pattern that identifies a maximum airflowrestriction by the corresponding bonding roller at the nip. Identify arepeating series of bond shapes lying in a row. Draw a line in the crossdirection which intersects these bond shapes at the position relativethe machine direction where the shapes occupy the greatest proportion ofthe distance along the cross direction line. It will be appreciated thatit may be necessary to take measurements along several cross directionlines to empirically and/or iteratively identify the one along which thebond shapes occupy the greatest proportion of the distance. With themeasuring tool, measure the length from the start of the repeatingseries to the corresponding location at the end of the repeating series(including distances between bonding shapes) to the nearest 0.001 mm.This is the repeat length in the cross direction. With the measuringtool, measure each of the lengths of the line segments on the crossdirection line that lie over the bond shapes, to the nearest 0.001 mm.Add the lengths of all of these line segments within the repeat length,and divide the total by the repeat length. Report to the nearest 0.001.This is the airflow restriction ratio. For example, in FIG. 5C, therepeat length w_(p) is measured along the cross direction line 107 a.The line segments lying over the bond shapes are w₁ through w₄. Theairflow restriction ration is the sum of lengths w₁ through w₄ dividedby the repeat length w_(p).

Cross-Nip Airflow Angle (β_(A))

The bond pattern may provide an airflow path that has a machinedirection vector component. Draw a line in the cross direction. Identifya line that can be drawn that extends past at least eight rows of bondshapes without intersecting a bond shape, if such a line exists. This isthe cross-nip airflow line. Extend this line to intersect the crossdirection line. Using the angle measurement tool, measure the smallerangle between the cross direction line and the airflow line and reportto the nearest 0.1 degree. For example, lines 109 in FIG. 5A and 109 inFIG. 6A are cross-nip airflow lines which intersect the cross directionlines 107 to form the cross-nip airflow angles β_(A).

Bond Area Percentage

Identify a single repeat pattern of bond shapes and areas between themand enlarge the image such that the repeat pattern fills the field ofview. In ImageJ, draw a rectangle that circumscribes the repeat pattern.Calculate area of the rectangle and record to the nearest 0.001 mm².Next, with the area tool, trace the individual bond shapes or portionsthereof that are entirely within the repeat pattern/rectangle andcalculate and add the areas of all bond shapes or portions thereof thatare within the repeat pattern/rectangle. Record to the nearest 0.001mm². Calculate as follows:Bond Area %=(Sum of areas of bond shapes within repeat pattern)/(totalarea of repeat pattern)×100%Repeat for a total of three non-adjacent regions randomly selectedacross the sample. Record as Percent Bond Area to the nearest 0.01%.Calculate the average and standard deviation of all 18 of the bond areapercentage measurements and report to the nearest 0.01%.

Average Individual Bond Area

Enlarge the image of a region of the sample such that edges of a bondshape can be identified. With the area tool, manually trace theperimeter of a bond. Calculate and record the area to the nearest 0.001mm². Repeat for a total of five non-adjacent bonds randomly selectedacross the total sample. Measurements are made on each sample. A totalof six samples are measured. Calculate the average and standarddeviation of all 30 bond area measurements and report to the nearest0.001 mm².

Article Measurements

Where measurement of dimensions of an assembled absorbent article (suchas a diaper) or features thereof are required, such as, e.g., tocalculate area of a surface, the article is laid out on a flat surface,and the article is drawn out longitudinally and laterally to the extentrequired to remove any slack in the backsheet or other outermost,outward-facing layer, that is present as a result of, e.g., folds,wrinkles or the presence of elastic members.

Compression Loft Coefficients of Friction

Specimen Preparation

(Backsheet Nonwoven Web)

To obtain the specimen, lay the sample diaper flat on a bench,wearer-facing surface downward, and measure the total longitudinallength of the article. Mark a first site on the backsheet that is 33% ofthe total length from the front waist of the article along itslongitudinal axis, and a second site that 33% of the total length fromthe back waist of the article along the longitudinal axis. Carefullyremove a portion of the nonwoven web layer from the backsheet ofsufficient size to yield the specimens. A cryogenic spray, such asCYTO-FREEZE (Control Company, Houston, Tex.), may be used to deactivateadhesives and enable easy separation of the nonwoven web layer from theunderlying film layer. Cut two square specimens from the removednonwoven web layer 65 mm by 65 mm each centered at one of the sitesidentified above, with their cut edges parallel and perpendicular,respectively, with the longitudinal axis of the diaper. Precondition thespecimens at about 23° C.±2 C.° and about 50%±2% relative humidity for 2hours prior to testing.

(Topsheet Nonwoven Web)

To obtain the specimen, lay the sample diaper flat on a bench,outward-facing surface downward, and measure the total longitudinallength of the article. Mark a first site on the topsheet that is 33% ofthe total length from the front waist of the article along itslongitudinal axis, and a second site that 33% of the total length fromthe back waist of the article along the longitudinal axis. Separate thenonwoven web material forming the uppermost layer of the topsheet fromany adhered underlying layers, using freeze spray if necessary todeactivate any adhesives. Cut two square specimens from the topsheetnonwoven web material 65 mm by 65 mm each centered at one of the sitesidentified above, with their cut edges parallel and perpendicular,respectively, with the longitudinal axis of the diaper. Precondition thespecimens at about 23° C.±2 C.° and about 50%±2% relative humidity for 2hours prior to testing.

Compression Loft

Compression caliper measurements are performed using an Ono Sokkidigital caliper (GS-503 Linear Gauge Sensor with DG-3610 Digital Gauge,Ono Sokki Co, Japan or equivalent) capable of measuring to the nearest0.01 mm. The circular foot's diameter is 50.8 mm and the appliedpressure is 0.5 kPa. The caliper is first zeroed by placing the footdirectly on the anvil and setting the digital gauge to zero. The foot isthen raised and the first specimen is placed onto the caliper anvil,with the body facing surface directed downward with the first testspecimen centered under the foot. The foot is lowered at about 5 mm/secuntil it rests on the specimen. Readings are taken after a residencetime of 5 sec and recorded to the nearest 0.01 mm. The foot is raisedand the measurement is repeated on the second specimen. A total of 10substantially identical samples are tested and the average of all 20caliper measurements reported as low compression caliper to the nearest0.01 mm.

The measurement apparatus is then reconfigured such that the circularfoot's diameter is 50.8 mm and the applied pressure is 4.14 kPa. Thecaliper is first zeroed by placing the foot directly on the anvil andsetting the digital gauge to zero. The foot is then raised and the firstspecimen is placed onto the caliper anvil, with the body facing surfacedirected downward with the first specimen centered under the foot. Thefoot is lowered at about 5 mm/sec until it rests on the specimen.Readings are taken after a residence time of 5 sec and recorded to thenearest 0.01 mm. The foot is raised and the measurement is repeated onthe second specimen. A total of 10 substantially identical samples aretested and the average of all 20 caliper measurements reported as highcompression caliper to the nearest 0.01 mm.The Compression Loft is calculated as [(low compression caliper)−(highcompression caliper)]/(low compression caliper)×100%.

Coefficients of Friction

The static and kinetic coefficients of friction can be measured usingASTM Method D 1894-01 with the following particulars. The test isperformed on a constant rate of extension tensile tester with computerinterface (a suitable instrument is the MTS Alliance using Testworks 4Software, as available from MTS Systems Corp., Eden Prairie, Minn.)fitted with a coefficient of friction fixture and sled as described in D1894-01 (a suitable fixture is the Coefficient of Friction Fixture andSled available from Instron Corp., Canton, Mass.). The apparatus isconfigured as depicted in FIG. 1c of ASTM 1894-01 using a stainlesssteel plane with a grind surface of 320 granulation as the targetsurface. A load cell is selected such that the measured forces arewithin 10% to 90% of the range of the cell. The tensile tester isprogrammed for a crosshead speed of 127 mm/min, and a total travel of130 mm. Data is collected at a rate of 100 Hz.

The specimen is cut down to a reduced size of 63.5 mm×63.5 mm (again,with cut edges parallel and perpendicular, respectively, with thelongitudinal axis of the diaper) and mounted onto the foam rubber sideof the sled using double sided adhesive tape (tape should be wide enoughto cover 100% of the sled's surface). The specimen is oriented on thesled such that the wearer-facing surface, or outward-facing surface (ason the diaper, according to whether the specimen was taken from topsheetor backsheet) will face the target surface, and the longitudinalorientation of the specimen, relative the longitudinal axis of thediaper, is parallel to the pull direction of the sled. The mass of thesled with mounted sample is recorded to 0.1 gram. The target surface ofthe stainless steel plane is cleaned with isopropanol before each test.

The static and kinetic coefficients of friction (COF) for the specimenare calculated as follows:Static COF=A _(S) /B

-   -   A_(S)=maximum peak force in grams force (gf) for the initial        peak    -   B=mass of sled in grams

Kinetic COF=A_(K)/B

-   -   A_(K)=average peak force in grams force (gf) between 20 mm and        128 mm    -   B=mass of sled in grams

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application, is hereby incorporated herein by reference in itsentirety unless expressly excluded or otherwise limited. The citation ofany document is not an admission that it is prior art with respect toany invention disclosed or claimed herein or that it alone, or in anycombination with any other reference or references, teaches, suggests ordiscloses any such invention. Further, to the extent that any meaning ordefinition of a term in this document conflicts with any meaning ordefinition of the same term in a document incorporated by reference, themeaning or definition assigned to that term in this document shallgovern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A disposable diaper, comprising: a topsheetcomprising a first nonwoven web; a backsheet comprising a secondnonwoven web which forms a portion of the outermost layer of the diaper;and an absorbent core comprising a particulate polymer material disposedbetween the topsheet and the outermost layer, wherein the absorbent coreis substantially cellulose free; wherein the first nonwoven web and thesecond nonwoven web have a combined basis weight of at least 50 gsm, andwherein a first basis weight of the first nonwoven web is different thana second basis weight of the second nonwoven web; wherein the ratio ofthe basis weight of the first nonwoven web to the basis weight of thesecond nonwoven web is from 30/70 to 70/30; and wherein each of thefirst nonwoven web and the second nonwoven web has a Compression Loft ofat least 30%, according to the Compression Loft Test.
 2. The disposablediaper of claim 1, wherein each of the first nonwoven web and the secondnonwoven web has a pre-conversion density of no greater than 65 kg/m³.3. The disposable diaper of claim 1, wherein the first nonwoven web andthe second nonwoven web comprise spunbond or spunbond-meltblown-spunbond(SMS) nonwoven webs.
 4. The disposable diaper of claim 3, wherein atleast one of the first nonwoven web or the second nonwoven web has amacroscopic surface approximating a plane, a machine direction and across direction perpendicular to the machine direction, wherein the atleast one or both of the first nonwoven web or the second nonwoven webis formed predominately of polymeric fibers and comprises a series ofone or more consolidating bonds impressed on the surface, wherein theone or more consolidating bonds having at least one bond shape, whereinthe series is repeated to form a pattern of consolidating bonds, whereinthe series is repeated in at least four rows extending predominately inthe cross direction, wherein the series is repeated in at least fourcolumns extending predominately in the machine direction, wherein thebond shape has a perimeter with a greatest measurable length and agreatest measurable width, and wherein the perimeter: has a convexportion; has an aspect ratio of the greatest measurable length to thegreatest measurable width of at least 2.5; and is oriented such that aline intersecting the perimeter along which the greatest measurablelength exists intersects an axis lying on the surface along the machinedirection to form a smaller angle of between 1 degree and 40 degrees. 5.The disposable diaper of claim 1, wherein the first nonwoven web and thesecond nonwoven web each have an opacity greater than 10%.
 6. Thedisposable diaper of claim 1, wherein the first nonwoven web forms atleast 50 percent of a wearer-facing planar surface area of the diaper asdefined and circumscribed by an outer profile of the diaper.
 7. Thedisposable diaper of claim 1, wherein the second nonwoven web forms atleast 50 percent of an outward-facing planar surface area of the diaperas defined and circumscribed by an outer profile of the diaper.
 8. Thedisposable diaper of claim 1, wherein the first nonwoven web forms atleast 50 percent of a wearer-facing planar surface area of the diaper asdefined and circumscribed by an outer profile of the diaper, wherein thesecond nonwoven web forms at least 50 percent of an outward-facingplanar surface area of the diaper as defined and circumscribed by theouter profile of the diaper, and wherein the first nonwoven web and thesecond nonwoven web are disposed in overlying/underlying positionsacross at least 50 percent of the wearer-facing planar surface area ofthe diaper as defined and circumscribed by the outer profile of thediaper.
 9. The disposable diaper of claim 1, wherein at least one of thefirst nonwoven web or the second nonwoven web has a static coefficientof friction equal to or less than 0.4.
 10. The disposable diaper ofclaim 9, wherein at least one of the first nonwoven web or the secondnonwoven web has a kinetic coefficient of friction equal to or less than0.35.
 11. The disposable diaper of claim 9, wherein the first nonwovenweb and the second nonwoven web have respective static coefficients offriction that are within 30 percent of each other and that aredifferent.
 12. The disposable diaper of claim 10, wherein the firstnonwoven web and the second nonwoven web have respective kineticcoefficients of friction that are within 30 percent of each other andthat are different.
 13. The disposable diaper of claim 1, wherein fibersforming at least one of the first nonwoven web or the second nonwovenweb are crimped.
 14. The disposable diaper of claim 13, wherein thecrimped fibers are multicomponent fibers, and wherein the multicomponentfibers have at least two polymer components having differing propertiesand disposed in either side-by-side configuration or eccentriccore/sheath configuration.
 15. The disposable diaper of claim 14 whereineach of the at least two polymer components comprise polypropylene. 16.The disposable diaper of claim 15, wherein at least one of the at leasttwo polymer components comprises polyethylene.
 17. The disposable diaperof claim 1, wherein the first nonwoven web and the second nonwoven webhave a combined basis weight of no more than 75 gsm.
 18. The disposablediaper of claim 1, wherein the first nonwoven web and the secondnonwoven web have a combined basis weight of no more than 65 gsm. 19.The disposable diaper of claim 1, wherein the first nonwoven web and thesecond nonwoven web have a combined basis weight of no more than 60 gsm.20. The disposable diaper of claim 1, wherein the substantiallycellulose free absorbent core has less than 10% cellulose fibers byweight.
 21. The disposable diaper of claim 1, wherein the absorbent corecomprises: a first substrate; a second substrate; and a thermoplasticadhesive material disposed on or within the particulate polymermaterial; wherein the particulate polymer material is disposedintermediate the first and second substrates.
 22. The disposable diaperof claim 1, wherein the ratio of the basis weight of the first nonwovenweb to the basis weight of the second nonwoven web is from 40/60 to60/40.
 23. The disposable diaper of claim 1, wherein the ratio of thebasis weight of the first nonwoven web to the basis weight of the secondnonwoven web is from 45/55 to 55/45.
 24. A disposable diaper,comprising: an innermost layer comprising a first nonwoven web; anoutermost layer comprising a second nonwoven web; and a substantiallycellulose free absorbent core positioned between the innermost layer andthe outermost layer, wherein the substantially cellulose free absorbentcore comprises: a first substrate; a second substrate; a thermoplasticadhesive material; and a particulate polymer material, wherein thethermoplastic adhesive material and the particulate polymer material arepositioned intermediate the first and second substrates; wherein thefirst nonwoven web and the second nonwoven web have a combined basisweight of at least 40 gsm, and wherein a basis weight of the firstnonwoven web is less than a basis weight of the second nonwoven web;wherein the ratio of the basis weight of the first nonwoven web to thebasis weight of the second nonwoven web is from 40/60 to 60/40; andwherein each of the first nonwoven web and the second nonwoven web has aCompression Loft of at least 30%, according to the Compression LoftTest.
 25. The disposable diaper of claim 24, wherein each of the firstnonwoven web and the second nonwoven web has a pre-conversion density ofno greater than 65 kg/m³.
 26. The disposable diaper of claim 24, whereinthe substantially cellulose free absorbent core comprises no more thanan immaterial amount of cellulose fibers.
 27. The disposable diaper ofclaim 24, wherein the first nonwoven web and the second nonwoven webhave a combined basis weight of at least 50 gsm.
 28. A disposablediaper, comprising: an innermost layer comprising a first nonwoven web;an outermost layer comprising a second nonwoven web; and a substantiallycellulose free absorbent core positioned between the innermost layer andthe outermost layer, wherein the substantially cellulose free absorbentcore comprises: a first nonwoven material; a second nonwoven material; athermoplastic adhesive material; and a particulate polymer material,wherein the thermoplastic adhesive material and the particulate polymermaterial are positioned intermediate the first and second nonwovenmaterials, and wherein the substantially cellulose free absorbent corecomprises no more than an immaterial amount of cellulose fibers; whereinthe first nonwoven web and the second nonwoven web have a combined basisweight of at least 30 gsm, wherein a first basis weight of the firstnonwoven web is different than a second basis weight of the secondnonwoven web; wherein the ratio of the basis weight of the firstnonwoven web to the basis weight of the second nonwoven web is from30/70 to 70/30; and wherein each of the first nonwoven web and thesecond nonwoven web has a Compression Loft of at least 30%, according tothe Compression Loft Test.
 29. The disposable diaper of claim 28,wherein the first nonwoven web and the second nonwoven web have acombined basis weight of at least 40 gsm.
 30. The disposable diaper ofclaim 28, wherein the first nonwoven web and the second nonwoven webhave a combined basis weight of at least 50 gsm.
 31. The disposablediaper of claim 29, wherein the ratio of the basis weight of the firstnonwoven web to the basis weight of the second nonwoven web is from40/60 to 60/40.
 32. The disposable diaper of claim 29, wherein the ratioof the basis weight of the first nonwoven web to the basis weight of thesecond nonwoven web is from 45/55 to 55/45.
 33. The disposable diaper ofclaim 29, wherein the first nonwoven web and the second nonwoven webeach have an opacity greater than 40%.
 34. The disposable diaper ofclaim 29, wherein each of the first nonwoven web and the second nonwovenweb has a Compression Loft of at least 50%, according to the CompressionLoft Test.
 35. The disposable diaper of claim 29, wherein each of thefirst nonwoven web and the second nonwoven web has a Compression Loft ofat least 70%, according to the Compression Loft Test.